--- name: "evms" section: "8" platform: "linux" package: "evms-cli" version: "2.5.5-18" release: "Debian 4.0 (Etch)" platforms: ["linux"] url: "https://new.carta.tech/evms" --- # evms(8) The evms command starts the Enterprise Volume Management System (EVMS) Command Line Interpreter (CLI). These command line options control where the EVMS CLI gets commands from and how it interprets those commands. This document begins by explaining the parameter option descriptions and then goes on to explain the commands that can be entered at the CLI's prompt. ## NAME evms - The **evms** command starts the Enterprise Volume Management System (EVMS) Command Line Interpreter (CLI). These command line options control where the EVMS CLI gets commands from and how it interprets those commands. This document begins by explaining the parameter option descriptions and then goes on to explain the commands that can be entered at the CLI's prompt. ## SYNOPSIS **evms** \[**-b**\] \[**-c**\] \[**-d** *debug-level*\] \[**-f** *filename*\] \[**-h**\] \[**-m** *engine-mode*\] \[**-n** *node*\] \[**-r** *parameter*\] \[**-s**\] \[**-p**\] \[**-v**\[**\[0-2\]**\]\] \[**-rl** *parameter* ...\]\] ## DESCRIPTION The CLI does not accept EVMS commands as part of the command line used to invoke it. The parameter options on the command line determine where the CLI gets the commands from and how it interprets those commands. By default, the CLI prompts the user for EVMS commands. To exit the EVMS CLI, type **quit** or **exit**. ## PARAMETER OPTIONS The following parameters are available for use during the initial call to invoke the EVMS CLI. - **-b** Tells the EVMS CLI to run in batch mode. Any time there is a prompt for input from the user, the default value should be accepted automatically. This is the default behavior with the **-f** option. - **-c** Indicates that changes are not committed to disk until the user exits the CLI. Normally, changes are committed to disk after each individual command is completed, even if there are multiple commands specified on the same command line. - **-d** *debug-level* sets the debug level that controls how much information is logged in */var/log/evms-engine.log*. *debug-level* is specified as one of the following: critical, serious, error, warning, default, details, extra, entry\_exit, debug, or everything. - **-f** *filename* tells the CLI to accept input from the file specified by *filename*. When all of the commands in *filename* have been processed, the CLI will exit. - **-h** Provides help on invoking the EVMS CLI. To get help on commands accepted by the CLI, invoke the Interpreter, enter the word **help** at the prompt, and press **Enter**. - **-m** *engine-mode* tells the CLI the mode in which it should open the EVMS Engine. *engine-mode* is either ReadOnly, ReadWrite, or Daemon. Daemon mode should only be specified when using the CLI to start the EVMS Engine daemon on nodes in a cluster. - **-n** *node* tells the CLI that all commands are intended for the given node name in a cluster. - **-p** Tells the CLI to parse commands only. Errors found during parsing will be reported, but the commands will not be executed. - **-r** Tells the CLI that the next command line argument is a replacement parameter. See examples below. - **-s** Tells the CLI to prompt for a single command line and then exit. Normally, the CLI will prompt for command lines until it receives the **quit** or **exit** command. - **-v** Enables verbose mode 2. - **-v0** Disables verbose mode. Verbose mode 0 allows EVMS Engine status messages to be discarded whenever changes are committed to disk. - **-v1** Enables verbose mode 1. Verbose mode 1 allows EVMS Engine status messages to be displayed whenever you commit changes to disk. The messages are displayed one per line on the screen. - **-v2** Enables verbose mode 2. Verbose mode 2 allows EVMS Engine status messages to be displayed whenever you commit changes to disk. The messages are displayed using a single line on the screen. This means that the current message is erased, and the next message is displayed in its place. - **-rl** tells the EVMS CLI that all of the remaining command line arguments are replacement parameters. Replacement parameters are accessed in EVMS commands using the $(x) notation, where x is a number identifying which replacement parameter to use. Replacement parameters are assigned numbers (starting with 1) as they are encountered on the command line. **Example:**\ ``` evms -c -f testcase -r sda -r sdb ``` **sda** is replacement parameter 1\ **sdb** is replacement parameter 2 **Example:**\ ``` evms -r sda -c -f testcase -rl sdb sdc ``` **sda** is replacement parameter 1\ **sdb** is replacement parameter 2\ **sdc** is replacement parameter 3 **Example:**\ ``` evms -c -f testcase -rl sda 100 ``` **sda** is replacement parameter 1\ **100** is replacement parameter 2 if testcase contains the command: ``` allocate:$(1)_freespace, size=$(2)MB ``` then this command becomes: ``` allocate: sda_freespace, size=100MB ``` ## COMMANDS FOR THE EVMS PROMPT The following commands can be typed at the EVMS CLI prompt "EVMS: ". This prompt appears when the EVMS CLI is ready to accept a command. All EVMS CLI commands and key words are case insensitive. The names and values that you supply are case sensitive. Any amount of whitespace can appear between commands, delimiters, and values. ### ACTIVATE The **Activate** command is used to activate volumes or storage objects that are not active. If any of the storage objects that the specified volume or storage object comprises are not active, they will be activated so that the specified volume or storage object can be activated. The Activate command has the following syntax: **Activate :** *name* where - **Activate** may be abbreviated as **act**. - *name* is the name of a volume or storage object. **Example:**\ Given a volume /dev/evms/mydata that is not active, activate the volume. ``` act:/dev/evms/mydata ``` ### ADD FEATURE The **Add Feature** command adds an EVMS feature to an existing EVMS native volume. The feature is added to the volume by shrinking the filesystem on the volume to make room for the metadata of the new feature. The metadata are then written on the volume. In order to successfully write the metadata for the feature on the volume, EVMS must have a Filesystem Interface Module (FSIM) for the filesystem on the volume, and the FSIM must support filesystem shrinking. If the volume cannot be unmounted (perhaps because it is root), the FSIM must support on-line shrinking of the filesystem. The filesystem must be able to be shrunk by an amount that is equal to or larger than the metadata of the feature. **CAUTION:** The **Add Feature** command should not be used on volumes that do not have a filesystem (such as databases) as data loss may occur. The add feature command has the following syntax: **Add Feature :** *feature* **= {** \[*name* **=** *value* \[**,** *name* **=** *value*\] ...\] **} ,** *volume* where - **Add Feature** may be abbreviated as **af**. - *feature* is the name of the EVMS feature to add to the volume. - *name* is the name of an option accepted by the feature. - *value* is an acceptable value for the option *name*. - *volume* is the name of an EVMS volume to which the *feature* is added. **Example:**\ The following command adds the feature "My\_Drive\_Link" to the volume, "My\_EVMS\_Volume." ``` af:DriveLink={Name=My_Drive_Link},/dev/evms/My_EVMS_Volume ``` ### ADD SEGMENT MANAGER The **Add Segment Manager** command is used to assign a segment manager to any disk or segment in the system that does not already have a Segment Manager assigned to it. The **Add Segment Manager** command has the following syntax: **Add Segment Manager :** *segment-mgr* **= {** \[*name* **=** *value* \[**,** *name* **=** *value*\] ...\] **} ,** *disk* where - **Add Segment Manager** can be abbreviated as **asm**. - *segment-mgr* is the name of the segment manager that is to be assigned to a disk. - *name* is the name of an option accepted by the segment manager. - *value* is an acceptable value for the option *name*. - *disk* is the name of the disk that the Segment Manager will be assigned to. The **Add Segment Manager** command is the same as the **Assign** command. See the section for the **Assign** command for an example. ### ALLOCATE The **Allocate** command is used to allocate regions or segments from blocks of freespace. The **Allocate** command has the following syntax: **Allocate :** *freespace* \[**,** *name* **=** *value*\] ... where - **Allocate** may be abbreviated as **a**. - *freespace* is the name of a region or segment which represents freespace, such as sdb\_freespace1. - *name* is the name of an option accepted by the region manager or segment manager which created *freespace*. - *value* is an acceptable value for the option *name*. **Example:**\ Given a disk with no partitions that is under the control of the DOS Segment Manager, create a 50 MB segment in an extended partition. The new segment does not have to be bootable. ``` a:sdb_freespace1,size=50MB,offset=0,primary=false,bootable=false ``` ### ASSIGN The **Assign** command is used to assign a segment manager to any disk or segment in the system that does not already have a Segment Manager assigned to it. The **Assign** command is the same as the **Add Segment Manager** command. The **Assign** command has the following syntax: **Assign :** *segment-mgr* **= {** \[*name* **=** *value* \[**,** *name* **=** *value*\] ...\] **} ,** *disk* where - **Assign** can be abbreviated as **as**. - *segment-mgr* is the name of the segment manager that is to be assigned to a disk. - *name* is the name of an option accepted by the segment manager. - *value* is an acceptable value for the option *name*. - *disk* is the name of the disk that the Segment Manager will be assigned to. **Example:**\ You have installed a brand new disk into your computer. You wish to partition this disk into multiple partitions using the DOS Segment Manager and the standard Linux partitioning scheme. What must you do before you can partition the disk? You must assign the DOS Segment Manager to the disk. If EVMS identifies the disk as sdb, the command to do this is: ``` as:DosSegMgr={TypeByName=Linux},sdb ``` The previous command will cause the DOS Segment Manager to assume control of the disk sdb and prepare the disk for partitioning. Two new storage objects will result from the **Assign** command: a metadata segment object and a freespace segment object. The freespace segment, sdb\_freespace1, is created to represent the space available on sdb. This space can be divided into data segments (partitions) using **Allocate** or **Create**. ### CHECK The **Check** command performs a consistency check on the filesystem contained within the specified volume. This command is the equivalent of the Linux **fsck** command. The **Check** command has the following syntax: **Check :** *volume* \[**,** *name* **=** *value*\] ... where - **Check** can be abbreviated as **ch**. - *volume* is the name of the volume with the filesystem to be checked. - *name* is the name of an option supported by the File System Interface Module (FSIM) for the filesystem found on the specified volume. - *value* is an acceptable value for option *name*. ### COMMIT The **Commit** command can be used when the EVMS CLI is running in alternate mode to force the CLI to save all changes since the last save. The **Commit** command is the same as the **Save** command. The EVMS CLI can run in either of two modes: default or alternate. The default mode writes to disk any changes made by a command immediately after that command is executed. The alternate mode, which is invoked by using the **-c** option on the command line that invoked the CLI, holds all changes in memory until the CLI exits. Once the CLI exits, all of the changes being held in memory are written to disk. This alternate mode can significantly improve performance in situations where large command files are executed or complex configurations are used. However, it is not always desirable to hold all changes in memory until the EVMS CLI exits. When the EVMS CLI is operating in default mode, the **Commit** command does nothing. When the EVMS CLI is operating in alternate mode, the **Commit** command forces the EVMS CLI to save all changes it has accumulated. This option effectively gives the user control over when changes are saved and when they are held in memory. The **Commit** command has the following syntax: **Commit** \[**: Hold\|Release**\] where - **Hold** tells the EVMS CLI to hold all changes in memory and to commit those changes to disk when the Interpreter exits. - **Release** tells the EVMS CLI to write all pending changes to disk immediately and write changes to disk after each command has been completed. ### COMMIT WITH THE HOLD KEYWORD **Example:**\ The EVMS CLI is operating it its default mode, with changes being committed to disk after each command. Change the Interpreter's mode of operation so that changes are held in memory until the Interpreter exits. ``` commit:hold ``` ### COMMIT WITH THE RELEASE KEYWORD **Example:**\ The EVMS CLI is operating in its alternate mode, with all changes being held in memory until the EVMS CLI exits. Change the EVMS CLI's mode of operation so that changes are committed to disk after each command and write to disk all changes that are currently being held in memory. ``` commit:release ``` ### COMMIT IN ALTERNATE MODE **Example:**\ The EVMS CLI is operating in its alternate mode, with all changes being held in memory until the EVMS CLI exits. Without changing the mode the Interpreter operates in, force the Interpreter to commit to disk all the changes it is currently holding in memory. ``` commit ``` ### CONVERT The **Convert** command has two forms. The first form converts an existing compatibility volume into an EVMS volume. The second form converts an EVMS volume into a compatibility volume. ### CONVERTING FROM COMPATIBILITY VOLUMES TO EVMS VOLUMES The **Convert** command converts an existing compatibility volume into an EVMS volume by adding EVMS metadata to the compatibility volume. If the compatibility volume does not contain a filesystem, EVMS can add its metadata to the volume and convert it. If the compatibility volume contains a filesystem, EVMS shrinks the filesystem to make room for the EVMS metadata. EVMS must have a filesystem interface module (FSIM) that corresponds to the compatibility volume's filesystem, and the FSIM must support filesystem shrinking. **CAUTION:** The **Convert** command should not be used on compatibility volumes that are being used without a filesystem (for example, databases) as data loss may occur. The **Convert** command has the following syntax when converting a compatibility volume to an EVMS volume: **Convert :** *volume* **, Name =** *new-name* where - **Convert** may be abbreviated as **co**. - *volume* is the name of the compatibility volume to be converted into an EVMS volume **Name** may be abbreviated as the single letter **n**. - *new-name* is the new name for the volume. Please note that the new volume names must be in quotation marks if they contain spaces or any non-alphanumeric characters. **Example:**\ The following command changes volume /dev/evms/hda3 into an EVMS volume named New\_EVMS\_Volume. ``` Co : /dev/evms/hda3 , N = New_EVMS_Volume ``` ### CONVERTING FROM EVMS VOLUMES TO COMPATIBILITY VOLUMES The **Convert** command converts an existing EVMS volume into a compatibility volume by removing any EVMS metadata on the volume. Currently, this conversion can only occur for EVMS volumes that have no features applied to them. The **Convert** command has the following syntax when attempting to convert an EVMS volume into a compatibility volume: **Convert :** *volume***, Compatibility** where - **Convert** may be abbreviated as **Co**. - *volume* is the name of the EVMS volume to be converted into a compatibility volume. - **Compatibility** is the EVMS keyword used to indicate that a compatibility volume is the type of the resulting volume. **Compatibility** may be abbreviated as the single letter **c**. **Example:**\ The following command changes EVMS volume /dev/evms/Data to a compatibility volume. ``` Co : /dev/evms/Data , C ``` ### CREATE The **Create** command is used to create containers, EVMS objects, regions, segments, and volumes. The different items the **Create** command generates can also be abbreviated as a single letter on the command line. The syntaxes for each of the **Create** command options are listed below: ### CREATING CONTAINERS **Create : Container ,** *plug-in* **= {** \[*name* **=** *value* \[**,** *name* **=** *value*\] ...\] **} ,** *object* \[**,** *object*\] ... where - **Create** can be abbreviated as **c**. - **Container** can be abbreviated as **c**. - *plug-in* is the name of the plug-in to use when creating the container. - *name* is the name of an option accepted by the plug-in. - *value* is an acceptable value for the option *name*. - *object* is the name of a storage object used in the creation of the container. **Example:**\ Given a system with three available hard drives (sdc, sdd, hdc), use the EVMS LVM Region Manager to combine these disks into a container called Sample\_Container with a PE (physical extent) size of 16MB. ``` c:c,LvmRegMgr={name=Sample_Container,pe_size=16MB},sdc,sdd,hdc ``` ### CREATING EVMS OBJECTS **Create : Object ,** *feature* **= {** \[*name* **=** *value* \[**,** *name* **=** *value*\] ...\] **} ,** *object* \[**,** *object*\] ... where - **Create** can be abbreviated as **c**. - **Object** can be abbreviated as **o**. - *feature* is the name of the EVMS Feature plug-in to use when creating the EVMS object. - *name* is the name of an option accepted by the region manager. - *value* is an acceptable value for the option *name*. - *object* is the name of a region, segment, disk, or EVMS object to be used in the creation of the new EVMS object. **Example:**\ Given a system with a volume /dev/evms/Source, and an available segment sdb5, create a snapshot object called "My\_Snapshot\_Object" using the EVMS SnapShot feature. /dev/evms/Source is the source of the snapshot, and sdb5 is the backing store for the snapshot. ``` c:o,Snapshot={original=/dev/evms/Source,snapshot=My_Snapshot_Object},sdb5 ``` ### CREATING REGIONS **Create : Region ,** *region-mgr* **= {** \[*name* **=** *value* \[**,** *name* **=** *value*\] ...\] **} ,** *object* \[**,** *object*\] ... where - **Create** can be abbreviated as **c**. - **Region** can be abbreviated as **r**. - *region-mgr* is the name of the Region Manager plug-in you want to use. - *name* is the name of an option accepted by the region manager. - *value* is an acceptable value for the option *name*. - *object* is the name of a region, segment, or disk to be used in the creation of the new region. ### CREATING SEGMENTS **Create : Segment ,** *freespace* \[**,** *name* **=** *value*\] ... where - **Create** can be abbreviated as **c**. - **Segment** can be abbreviated as **s**. - *freespace* is the name of a segment representing freespace. - *name* is the name of an option accepted by the segment manager that created the *freespace*. - *value* is an acceptable value for the option *name*. **Example:**\ Given a disk that is under the control of the DOS Segment Manager, has no primary partitions, and has a 200 MB freespace segment called sdb\_freespace1, create a 50 MB logical segment. The new segment does not have to be bootable. ``` c:s,sdb_freespace1,size=50MB,offset=0,primary=false,bootable=false ``` ### CREATING COMPATIBILITY VOLUMES **Create : Volume ,** *object* **, Compatibility** where - **Create** can be abbreviated as **c**. - **Volume** can be abbreviated as **v**. - *object* is the name of the disk, segment or region that will become a volume. **Example:**\ Given a system with an unused segment sda3, turn this segment into a compatibility volume. ``` c:v,sda3,c ``` ### CREATING EVMS VOLUMES **Create : Volume ,** *object* **, Name =** *name* where - **Create** can be abbreviated as **c**. - **Volume** can be abbreviated as **v**. - *object* is any disk, segment, region, or EVMS object that is not already a volume or a part of a volume, storage object, or storage container. - *name* is the name that you would like the volume to have. This name must be unique throughout the system, and the volume, once created, will be known as /dev/evms/*name*. **Example:**\ Given a system with an unused segment sda3, make sda3 an EVMS volume known as Widow\_Maker. ``` c:v,sda3,n=Widow_Maker ``` ### DEACTIVATE The **Deactivate** command is used to deactivate volumes or storage objects that are active. When a storage object is deactivated, all of the storage objects and volumes that are built using the specified storage object will also be deactivated, since active objects and volumes cannot be built from inactive objects. The Deactivate command has the following syntax: **Deactivate :** *name* where - **Deactivate** may be abbreviated as **deact**. - *name* is the name of a volume or storage object. **Example:**\ Given a volume /dev/evms/mydata that is active, deactivate the volume. ``` deact:/dev/evms/mydata ``` ### DELETE The **Delete** command deletes a volume, container EVMS object, region, or segment from the system. The **Delete** command has the following form: **Delete :** *name* where - **Delete** can be abbreviated as **d**. - *name* is the name of the volume, container, EVMS object, region, or segment that is to be deleted. ### ECHO The **Echo** command echoes a string to the standard output. **Echo** allows the user to output user defined text from an EVMS command file. The **Echo** command has the following syntax: **Echo :** *String* where - *String* is any sequence of ASCII characters except quotation marks. A string should be enclosed in quotation marks if it contains any non-alphabetic or non-numeric characters or spaces. If a quotation mark is embedded in the string as part of the string, then quotation marks should also surround the embedded string, as in the example below: **Example:** ``` Echo : "This is a ""sample"" string with embedded quotation marks." ``` ### EXIT The **Exit** command is used to exit the EVMS CLI. The **Exit** command is the same as the **Quit** command. ### EXPAND The **Expand** command is used to increase the size of a volume, storage container, or storage object. Listed below are the two syntaxes of the **expand** command. The first syntax is for increasing the size of storage containers. The second syntax of **Expand** is for increasing the size of volumes and storage objects. **Increasing the Size of a Storage Container** Storage Containers are expanded by adding segments or regions to them. When expanding containers, the **Expand** command has the following syntax: **Expand :** *container* **,** *object* \[**,** *object*\] ... where - **Expand** can be abbreviated as **e**. - *container* is the name of the container to expand. - *object* is the name of a disk. segment or region to add to the container specified by *container*. **Increasing the Size of a Volume or Storage Object** An EVMS volume or storage object can be comprised of one or more EVMS objects, regions, segments, or disks. Whether a volume or storage object can be expanded or not depends on how it is constructed. For example, if a volume consists of a single segment with no EVMS features applied to it, then it can only be expanded if the Segment Manager that created the segment can increase the size of that segment. EVMS allows complete control over how a volume is expanded. A more complicated volume may have several ways to expand. For example, a volume created from several segments using EVMS Drive Linking can be expanded by increasing the size of the last segment in the drive link. You can also expand the volume by using EVMS Drive Linking to add another segment to the volume. When a volume can be expanded in multiple ways, we say that the volume has multiple expansion points. To expand a volume, you must specify which expansion point to use. The same is true for storage objects. In the example from the paragraph above, there are two expansion points. One expansion point is the EVMS object created by EVMS Drive Linking. This EVMS object could be expanded by adding another segment to it. The second expansion point is the last segment used in the EVMS object formed by EVMS Drive Linking. While the other segments used to create this EVMS object may be capable of being expanded, EVMS Drive Linking allows only the last segment to be expanded. To find the expansion points for a storage object or volume, use the **Query Expand Points** command. Once you know the expansion points for a volume or storage object, these points can be used to expand the volume or storage object. When increasing the size of a volume or storage object the **Expand** command has the following syntax: **Expand :** *expansion-point* \[**,** *name* **=** *value*\] ... \[**,** *object*\] ... where - **Expand** can be abbreviated as **e**. - *expansion-point* is the name of an expansion point as provided by the **Query Expand Points** command. - *name* is the name of an option supported by the plug-in module that controls *Expansion-Point*. - *value* is an acceptable value for the option *Name*. - *object* is the name of an acceptable EVMS object, region, segment, freespace, or disk to use for expanding the volume. **Example:**\ This example assumes that there is a volume created from three segments using EVMS Drive Linking. The three segments are sda1, sdb1, and sdc1. The EVMS object created by EVMS Drive Linking is called DL1, and the volume is called /dev/evms/Sample\_Volume. The segment sdc1 is controlled by the DOS Segment Manager (DosSegMgr), and has a 50 MB block of freespace (sdc\_freespace1) adjacent to it on the disk. Also, there is an unused 200 MB segment known as hda7 available in the system. The **Query Expand Points** command indicates that this volume has two expansion points: DL1 and sdc1. Expand this volume by 250 MB. First, we must consider the order in which we will use the expand points to expand the volume. Currently, sdc1 is an expand point. Since EVMS Drive Linking allows only the last segment it is linking to be expanded, sdc1 must be the last segment that EVMS Drive Linking uses to create DL1. If we add hda7 to DL1, then hda7 will become the last segment used in DL1, and sdc1 will not be an expansion point anymore. Without being able to expand sdc1, we will not be able to reach our goal of expanding the volume by 250 MB. However, expanding sdc1 has no effect on our ability to add hda7 to DL1, so if we expand sdc1 before we add hda7 to DL1, we will be able to achieve our goal of expanding the volume by 250 MB. Completing our expansion will require two commands. First, to expand sdc1, we use: ``` e:sdc1,size=50MB,sdc_freespace1 ``` Now, to add hda7 to DL1, use the command: ``` e:DL1,hda7 ``` The resulting change is that the volume is 250 MB larger than before. ### FORMAT The **Format** command creates a filesystem on a volume. This is the equivalent of the Linux **mkfs** command. The **Format** command is the same as the **Mkfs** command. The **Format** command has the following syntax: **Format :** *FSIM* **= {** \[*name* **=** *value* \[**,** *name* **=** *value*\] ...\] **} ,** *volume* where - **Format** can be abbreviated as **f**. - *FSIM* is the name of a File System Interface Module recognized by EVMS. The specified FSIM is used to create the filesystem on the volume specified by *volume*. Normally there is one FSIM for each filesystem, so specifying the FSIM is the same as specifying the filesystem. In cases where one FSIM supports more than one filesystem, you can use an option to specify which filesystem should be created. - *name* is the name of an option supported by the FSIM for the filesystem found on the specified volume. - *value* is an acceptable value for the option *Name*. - *volume* is the name of the volume where the filesystem is to be created. ### HELP The CLI offers help on the essential commands. To obtain detailed help on an EVMS command, type the following: **Help :** *command* The CLI supports the following commands: - **Activate** activates volumes and storage objects. - **Add Feature** adds the specified feature to an existing EVMS volume. - **Add Segment Manager** attempts to add the specified segment manager to a disk or segment. (Same as **Assign**.) - **Allocate** allocates regions and segments from freespace. - **Assign** assigns a segment manager to a disk or segment. (Same as **Add Segment Manager**.) - **Check** performs an **fsck** on a volume. - **Commit** causes any changes that have not yet been written to disk to be written to disk. (Same as **Save**.) - **Convert** converts a compatibility volume into an EVMS volume or an EVMS volume into a compatibility volume. - **Create** creates volumes, EVMS objects, regions, segments, and containers. - **Deactivate** deactivates volumes and storage objects. - **Delete** deletes volumes, containers, EVMS objects, regions, and segments. - **Echo** echoes a string to standard output. - **Exit** exits the EVMS CLI. (Same as **Quit**.) - **Expand** expands the size of volumes, containers, EVMS objects, regions, and segments. - **Format** performs a **mkfs** operation on a volume. (Same as **Mkfs**.) - **Help** provides help on a specific EVMS command. - **Mkfs** creates a filesystem on a volume. (Same as **Format**.) - **Modify** modifies some of the options associated with a container, EVMS object, region, segment, or disk. - **Mount** mounts a volume on a directory. - **Probe** causes EVMS to check the system for hardware changes. - **Query** gathers information about the volumes, containers, EVMS objects, regions, and segments in the system. - **Quit** exits the EVMS CLI. (Same as **Exit**.) - **Remove** removes the segment manager assigned to a disk or segment. - **Rename** changes the names of volumes. - **Replace** replace a storage object with another storage object. - **Revert** deconstructs a volume or storage object a layer at a time. - **Save** causes any changes which have not yet been written to disk to be written to disk. (Same as **Commit**.) - **Set** modifies some of the options associated with a container, EVMS object, region, segment, or disk. - **Shrink** reduces the size of volumes, containers, EVMS objects, regions, and segments. - **Task** allows access to plug-in specific functions. - **Unformat** removes a filesystem from a volume. The contents of the filesystem are lost. - **UnMkfs** removes a file system from a volume. The contents of the volume are lost. - **Unmount** unmounts a volume. **Example:**\ Get detailed help on the **Create** command. ``` Help: Create ``` ### MKFS The **mkfs** command creates a filesystem on a volume. The **Mkfs** command is the same as the **Format** command. The **mkfs** command has the following syntax: **mkfs :** *FSIM* **= {** \[*name* **=** *value* \[**,** *name* **=** *value*\] ...\] **} ,** *volume* where - *FSIM* is the name of a File System Interface Module recognized by EVMS. The specified FSIM is used to create the filesystem on the volume specified by *volume*. Normally there is one FSIM for each filesystem, so specifying the FSIM is the same as specifying the filesystem. In cases where one FSIM supports more than one filesystem, you can use an option to specify which filesystem should be created. - *name* is the name of an option supported by the FSIM for the filesystem found on the specified volume. - *value* is an acceptable value for the option *name*. - *volume* is the name of the volume where the filesystem is to be created. ### MODIFY The **Modify** command changes options on EVMS objects, regions, containers, segments, or disks. If a Query command which returns EVMS objects, regions, containers, segments, or disks is executed using the List Options pseudo filter, then the changeable options for each item returned will be listed with that item. The **Modify** command has the following syntax: **Modify :** *item* **,** *name* **=** *value* \[**,** *name* **=** *value*\] ... where - *item* is the name of a EVMS object, region, container, segment or disk whose options are to be changed. - *name* is the name of an option that can be set for *item*. - *value* is an acceptable value for option *name*. ### MOUNT The **Mount** command mounts a volume on a directory. The **Mount** command has the following syntax: **Mount :** *volume* **,** *mount-point* \[**,** *mount-options*\] where - *volume* is the name of the volume to be mounted. - *mount-point* is the name of the directory on which to mount the volume. - *mount-options* is a string of options to be passed to the mount command. ### PROBE The **Probe** command is used to probe the system for hardware changes. This command is useful when the media in a removable media device has been changed. The **Probe** command will commit any pending changes (from prior commands) to disk before probing the system for hardware changes, even if the **-c** option was used when invoking the CLI. **Probe** can be abbreviated as a single letter **p** on the command line. ### QUERY The **Query** command is used to obtain information about the states of the volumes, EVMS objects, regions, containers, segments, and disks in the system. The **Query** command has several different syntaxes. One syntax is used for gathering information about the volumes, EVMS objects, regions, containers, segments, disks, and plug-in modules in the system. The other syntax for the **Query** command is used for gathering information related to various tasks that you can perform on items in the system. To gather information about volumes, containers, EVMS objects, regions, segments, disks, or plug-in modules, use this syntax of the **Query** command: **Query :** *data-type* \[**,** *filter*\] ... where - **Query** can be abbreviated as the single letter **q**. - *data-type* is either: - **plug-ins** (abbreviated as **p**) - **volumes** (abbreviated as **v**) - **containers** (abbreviated as **c**) - **objects** (abbreviated as **o**) - **regions** (abbreviated as **r**) - **segments** (abbreviated as **s**) - **disks** (abbreviated as **d**) - *filter* is one of the available filters for the type of data being returned. A filter restricts what is returned based upon some characteristic of the items being returned. The available filters for a query depend upon *data-type*. When processing a query like the one above, the CLI gathers items in the system of *data-type*. The interpreter puts these items into a list called the Return Values List. Each of the filters you specified examines the Return Values List and removes any items that do not fit the filter criteria. Once all of the filters have processed the Return Values List, the CLI displays the items that remain in the Return Values List. **NOTE:** Not all filters will work with every query. Furthermore, some filters may be mutually exclusive. See the EVMS Command Line Grammar to determine which combinations of filters are allowed for a particular query. ### SUPPORTED FILTERS The EVMS Command Line Interpreter supports the following filters: **Plug-in Type Filter** The plug-in **Type** filter is only available when *data-type* is equal to plug-ins. This filter removes from the Return Values List any entries for plug-in modules that are not of the type specified. The syntax for this filter is: **Type =** *plugin-type* where - **Type** can be abbreviated as the single letter **t**. - *plugin-type* is one of the following: - device manager (abbreviated as **d**) - segment manager (abbreviated as **s**) - region manager (abbreviated as **r**) - feature (abbreviated as **f**) - filesystem interface module (abbreviated as **FSIM**) - cluster management (abbreviated as **CM**) **Plugin Filter** The **Plugin** filter is available when *data-type* is either **volumes**, **objects**, **regions**, **containers**, **segments**, **disks**, or **plug-ins**. This filter removes any entries that have no association with the specified plug-in module from the Return Values List. - • For volumes and storage objects, any volume that was created without the use of the specified plug-in module is removed from the Return Values List. - • For regions, any region not created by the specified plug-in module is removed from the Return Values List. - • For containers, any container not created by the specified plug-in module is removed from the Return Values List. - • For segments, any segment not created by the specified plug-in module is removed from the Return Values List. - • For disks, any disk not claimed by the specified plug-in module is removed from the Return Values List. - • For plug-in modules, all plug-in modules other than the one specified are removed from the Return Values List. The syntax of the **Plugin** filter is: **Plugin =** *plug-in* where - **Plugin** can be abbreviated as the single letter **p**. - *plug-in* is the name or ID number of a plug-in module. **Volume Filter** The **Volume** filter is available when *data-type* is either **plug-ins**, **objects**, **regions**, segments, or **disks**. This filter removes from the Return Values List any item that was not used in the construction of the specified volume. The syntax for the **Volume** filter is: **Volume =** *volume* where - **Volume** can be abbreviated as the single letter **v**. - *volume* is the fully qualified name of a volume. **Object Filter** The **Object** filter is available when *data-type* is either **plug-ins**, **volumes**, **objects**, **regions**, **segments**, or **disks**. This filter removes from the Return Values List items that either did not create the specified object, or were created without using the specified storage object. The Object filter removes from the Return Values List each of the following: - • For **plug-ins**, the filter removes all plug-in modules except for those that are needed to create the specified storage object. - • For **volumes**, the filter removes any volume that does not use the specified storage object. - • For **objects**, **regions**, **segments**, and **disks**, the filter removes any storage object that was not used in the creation of the specified storage object. The syntax of the **Object** filter is: **Object =** *name* where - **Object** can be abbreviated as the single letter **o**. - *name* is the name of an object that EVMS has discovered. **Container Filter** The **Container** filter is available when *data-type* is either **plugins**, **volumes**, **objects**, **regions**, or **segments**. The list below explains what the Container filter removes from the Return Values List when *data-type* is one of the following: - • For **plug-ins**, the filter removes all plug-ins that were not used to create the container. - • For **volumes**, the filter removes any volume constructed without using a region from the specified container. - • For **objects**, the filter removes any object constructed without using a region from the specified container. - • For **regions**, the filter removes any regions that do not come from the specified container. - • For **segments**, the filter removes any segment that was not used to create the container. The syntax of the **Container** filter is: **Container =** *name* where - **Container** can be abbreviated as the single letter **c**. - *name* is the name of a container that EVMS has discovered. **Region Filter** The **Region** filter is available when *data-type* is either **volumes**, **objects**, or **containers**. The list below explains what the Region filter removes from the Return Values List when *data-type* is one of the following: - • For **volumes**, this filter removes any volume constructed without using the specified region. - • For **objects**, this filter removes any object constructed without using the specified region. - • For **containers**, this filter removes any container other than the one it came from. The syntax of the **Region** filter is: **Region =** *name* where - **Region** can be abbreviated as the single letter **r**. - *name* is the name of a region that EVMS has discovered. **Disk Filter** The **Disk** filter is available when *data-type* is **segments**. This filter removes from the Return Values List any segment which does not lie on the specified disk. The syntax of the **Disk** filter is: **Disk =** *name* where - **Disk** can be abbreviated as the single letter **d**. - *name* is the name of a disk that EVMS knows about. **Size Filters** There are three size filters: less than, greater than, and equal to. These filters are available when *data-type* is either **volumes**, **containers**, **objects**, **regions**, **segments**, or **disks**. These filters remove items from the Return Values List based upon their size. The Less Than filter has the following syntax: **LT** *n* *unit* where - *n* is a positive integer or 0. - *unit* is either KB, MB, GB, or TB. The Greater Than filter has the following syntax: **GT** *n* *unit* where - *n* is a positive integer or 0. - *unit* is either KB, MB, GB, or TB. The Equal filter has the following syntax: **EQ** *n* *unit* **,** *precision* where - *n* is a positive integer or 0. - *unit* if specified, must be either KB, MB, GB, or TB. - *precision* is a positive integer. *precision* indicates how "sloppy" a match to make. If no unit is specified, then *precision* is interpreted to be a percentage. If *precision* is seen as a percentage, the value is considered to be equal to *n* as long as the value is within *n* plus or minus *precision* percent of *n*. If a unit (KB, MB, GB, TB) is specified for *precision*, then a value is considered equal to *n* if the value is within the range of *n* - *precision* to *n* + *precision*. **Freespace Filter** The **Freespace** filter removes any items that do not contain freespace from the Return Values List. This filter is only useable when *data-type* is containers. The syntax of the **Freespace** filter is: **Freespace ,** *size-filters* where - **Freespace** can be abbreviated as the single letter **f**. - *size-filters* These filters are the same Size filters used with other filters, only now, instead of using the size of the containers for comparisons, the *size-filters* will use the freespace in the containers for comparisons. **Expandable Filter** The **Expandable** filter is available when *data-type* is either volumes, regions, objects, or segments. This filter removes any items that cannot be expanded from the Return Values List. The syntax of this filter is: **Expandable** where - **Expandable** can be abbreviated as the single letter **e**. **Shrinkable Filter** The **Shrinkable** filter is available when *data-type* is either volumes, regions, objects, or segments. This filter removes any items that cannot be shrunk from the Return Values List. The syntax of this filter is: **Shrinkable** where - **Shrinkable** can be abbreviated as the single letter **s**. **Unclaimed Filter** The **Unclaimed** filter is available when *data-type* is disks. This filter removes all disks which have been claimed by a Segment Manager plug-in module (disks that have a recognized partitioning scheme in place) from the Return Values List. The disks left in the Return Values List will either have no partitioning scheme, or the partitioning scheme is unrecognized. The syntax of this filter is: **Unclaimed** where - **Unclaimed** can be abbreviated as the single letter **u**. **List Options Pseudo Filter** **List Options** is treated like a filter, but it actually causes the CLI to list what can be done with each item in the Return Values List. The syntax of this filter is: **List Options** where - **List Options** can be abbreviated with the letters **lo**. ### SAMPLE QUERIES USING FILTERS - • To query the plug-ins in the system and their options: ``` q:p,lo ``` - • To query only the region manager plug-ins in the system and their options: ``` q:p,t=r,lo ``` - • To query the volumes in the system: ``` q:v ``` - • To query the volumes in the system over 1GB in size: ``` q:v,gt 1GB ``` - • To query the storage objects in the system: ``` q:o ``` - • To query the segments in the system that reside on disk sda: ``` q:s,d=sda ``` - • To query the segments in the system that belong to the container lvm/MyStuff, are over 500 MB in size and less than 2 GB in size, and come from disk sda: ``` q:s,c=lvm/MyStuff,GT 500MB,lt 2GB,d=sda ``` ### SPECIALTY QUERY COMMANDS The following commands allow for specialty queries. **Query Children** The **Query Children** command returns items that were used to create the specified item. For example, the children of a storage object are the EVMS objects, regions, disks, or segments that were used to create the specified storage object. The syntax of this command is: **Query : Children ,** *name* where - **Children** can be abbreviated as **chi**. - *name* is the name of a volume, EVMS object, region, segment, or container. **Query Parent** The **Query Parent** command returns the item (if there is one) that uses the specified item. For example, if a storage object is specified, then this command will return the volume or storage object which was created using the specified storage object, if such a volume or storage object exists. The syntax of this command is: **Query : Parent ,** *name* where - **Parent** can be abbreviated as **par**. - *name* is the name of a storage object, region, segment, container, or disk. **Query Expand Points** The **Query Expand Points** returns the expansion points for a volume or storage object. The expansion points for a volume or storage object are those entities within the volume or storage object that can be expanded without causing a loss of data. The syntax of this command is: **Query : Expand Points ,** *name* where - **Expand Points** can be abbreviated as **ep**. - *name* is the name of a storage object or volume. **Query Shrink Points** **Query Shrink Points** returns the shrink points for a volume or storage object. The shrink points for a volume or storage object are those entities within the volume or storage object that can be shrunk without causing a loss of data. The syntax of this command is: **Query : Shrink Points ,** *name* where - **Shrink Points** can be abbreviated as **sp**. - *name* is the name of a Storage Object or Volume. **Query Extended Info** **Query Extended Info** command allows access to any additional information that may be available for a plug-in module, a EVMS object, a region, a segment, a disk, or a container. The syntax of this command is: **Query : Extended Info ,** *name* \[**,** *field*\] where - **Extended Info** can be abbreviated as **ei**. - *name* is the name of a EVMS object, disk, region, segment, container, or plug-in module. It can also be the numeric ID of a plug-in module. - *field* is the name of a specific piece of extended information. Extended Information is grouped into fields. Each field has a name and one or more values associated with it. **Query Acceptable** The **Query Acceptable** allows you to discover which EVMS objects, regions, segments, or disks are acceptable for creating or expanding a volume, EVMS object, region, or segment. The command works as follows: When you create containers, objects, or regions, specify the following: the plug-in module being used, the values for the options that the plug-in module is to use when creating the container/object/region, and the EVMS objects, regions, segments, or disks that you have decided to use. The query will return any EVMS objects, regions, segments, or disks that are still available and acceptable for use in creating the container/object/region. **Example:**\ An example of using this command would be to determine what segments should be used to create a software RAID 5 storage object. Initially, no segments have been selected, so all unused segments in the system might be available and might be returned by this query. Choose an initial segment, which causes all segments on the same drive to not be acceptable anymore. To find out what segments are still available, use this query again and specify the segments that have already been chosen. This query will return all of the segments that might still be chosen. To see which segments are still available, choose another segment, and use this query again, specifying all of the segments that have already been chosen in the order in which they were chosen. You can use this iterative process to build an ordered list of segments. From this list you can see what segments you can use in an actual create command to create the desired software RAID 5 storage object. When expanding volumes or storage objects, specify the volume or storage object to be expanded along with any EVMS objects, segments, regions, or disks that you have already chosen to use in the expansion. This query will return the EVMS objects, regions, segments, or disks that you can still select and use to expand the specified volume or storage object. As described above, an iterative process can be used to build an ordered list of the EVMS objects, regions, segments, or disks that can be used to expand the specified volume or storage object with an actual expand command. The **Query Acceptable** command has two syntaxes: one for use with **Create**, the other for use with **Expand**. **Create** For determining what is acceptable for use with **Create**, use the following syntax: **Query : Acceptable, Create ,** *type***,** *plug-in* **= {** \[*name* **=** *value* \[**,** *name* **=** *value*\] ...\] **} ,** *object* \[**,** *object*\] ... where - **Acceptable** can be abbreviated as the single letter **a**. - **Create** can be abbreviated as the single letter **c**. - *type* is either **object**, **region**, or **container**. **object** can be abbreviated as a single letter **o**. **region** can be abbreviated as a single letter **r**. **container** can be abbreviated as a single letter **c**. - *plug-in* is the name or ID number of the plug-in module to use when creating *type*. - *name* is the name of an option supported by *plug-in*. - *value* is a legitimate value for the option *name*. - *object* is the name of a EVMS object, region, segment or disk which is to be used to create *type*. **Expand** For determining what is acceptable for use with **Expand**, use the following syntax: **Query : Acceptable , Expand ,** *expansion-point* **,** *object* \[**,** *object*\] ... where - **Acceptable** can be abbreviated by the single letter **a**. - **Expand** can be abbreviated by the single letter **e**. - *expansion-point* is the name of a volume or storage object that is to be expanded. - *object* is the EVMS name of a EVMS object, region, segment or disk which is to be used when expanding *expansion-point*. ### QUIT The **Quit** command is used to exit the EVMS CLI. The **Quit** command is the same as the **Exit** command. ### REMOVE The **Remove** command is used to remove a segment manager from a disk. A segment manager can only be removed from a disk when all of the data segments on that disk have been deleted. The **Remove** command causes a Segment Manager to remove its metadata from the disk, thereby leaving an empty disk. The empty disk can be used directly, or another segment manager can be assigned to it. The **Remove** command has the following syntax: **Remove :** *name* where - **Remove** can be abbreviated as **rem**. - *name* is the name of a disk that EVMS knows about. **Example:**\ This example will assume that you have a disk, sdb, and that this disk has several partitions on it that are managed by the DOS Segment Manager. The data segments on disk sdb are not being consumed by any EVMS object and could be deleted. Assume that you have a drive link that is aggregating several disks and that you would like to expand the drive link with the addition of disk sdb. In order for disk sdb to become an acceptable object for expanding the drive link, you must remove the segment manager and all the partitions from the disk. After deleting all the data segments on disk sdb, use the following command: ``` Rem:sdb ``` ### RENAME The **Rename** command is used to change the name of an EVMS volume. The **Rename** command has the following syntax: **Rename :** *volume* **, Name =** *new-name* where - **Rename** can be abbreviated as the single letter **r**. - *volume* is the name of the volume that needs to be changed. - **Name** can be abbreviated as the single letter **n**. - *new-name* is the new name for the volume. Please note that the new volume name must be in quotation marks if it contains spaces or any non-alphanumeric characters. **Example:**\ Rename the volume /dev/evms/John to /dev/evms/Fred. ``` r:/dev/evms/John,n=Fred ``` ### REVERT The **Revert** command strips away the topmost layer of an EVMS volume or storage object and restores it to its previous EVMS state. Thus, an EVMS Volume will revert to the EVMS Storage Object that it came from. The **Revert** command has the following syntax: **Revert :** *name* where - **Revert** can be abbreviated as **rev**. - *name* is the name of the volume or storage object to revert. **Example:**\ In this example, assume that you have just created a storage object named "Fred" from a storage object named "Barney." Fred is a complicated storage object that would take time to recreate. However, after creating Fred, you find out that you applied the wrong feature to Barney to create Fred. To remove the feature that was applied to Barney to create Fred without having to delete Fred and start from scratch, type the following command: ``` Rev:Fred ``` The **Revert** command will strip away the top most feature on Fred undoing the creation of Fred and leaving Barney. ### SAVE The **Save** command can be used when the EVMS CLI is running in alternate mode to force the CLI to save all changes since the last save. The **Save** command is the same as the **Commit** command. The EVMS CLI can run in either of two modes: default or alternate. The default mode writes to disk any changes made by a command immediately after that command is executed. The alternate mode, which is invoked by using the **-c** option on the command line that invoked the CLI, holds all changes in memory until the CLI exits. Once the CLI exits, all of the changes being held in memory are written to disk. This alternate mode can significantly improve performance in situations where large command files are executed or complex configurations are used. However, it is not always desirable to hold all changes in memory until the EVMS CLI exits. When the EVMS CLI is operating in default mode, the **Save** command does nothing. When the EVMS CLI is operating in alternate mode, the **Save** command forces the EVMS CLI to save all changes it has accumulated. This option effectively gives the user control over when changes are saved and when they are held in memory. The **Save** command has the following syntax: **Save** \[**: Hold\|Release**\] where - **Hold** tells the EVMS CLI to hold all changes in memory and to save those changes to disk when the Interpreter exits. - **Release** tells the EVMS CLI to write all pending changes to disk immediately and write changes to disk after each command has been completed. ### SAVE WITH THE HOLD KEYWORD **Example:**\ The EVMS CLI is operating it its default mode, with changes being saved to disk after each command. Change the Interpreter's mode of operation so that changes are held in memory until the Interpreter exits. ``` save:hold ``` ### SAVE WITH THE RELEASE KEYWORD **Example:**\ The EVMS CLI is operating in its alternate mode, with all changes being held in memory until the EVMS CLI exits. Change the EVMS CLI's mode of operation so that changes are saved to disk after each command and write to disk all changes that are currently being held in memory. ``` save:release ``` ### SAVE IN ALTERNATE MODE **Example:**\ The EVMS CLI is operating in its alternate mode, with all changes being held in memory until the EVMS CLI exits. Without changing the mode the Interpreter operates in, force the Interpreter to save to disk all the changes it is currently holding in memory. ``` save ``` ### SET The **Set** command changes options on EVMS objects, regions, containers, segments, or disks. If a Query command which returns EVMS objects, regions, containers, segments, or disks is executed using the List Options pseudo filter, then the changeable options for each item returned will be listed with that item. The **Set** command has the following syntax: **Set :** *item* **,** *name* **=** *value* \[**,** *name* **=** *value*\] ... where - *item* is the name of a EVMS object, region, container, segment or disk whose options are to be changed. - *name* is the name of an option that can be set for *item*. - *value* is an acceptable value for option *name*. ### SHRINK The **Shrink** command reduces the size of a volume, storage object, or storage container. **Reducing the Size of a Storage Container** You can reduce the size of a storage container by removing one or more of the segments or regions it contains. The **Shrink** command has the following syntax when used with storage containers: **Shrink :** *container* **,** *object* \[**,** *object*\] ... where - **Shrink** can be abbreviated as the letter **s**. - *container* is the name of the storage container to shrink. - *object* is the name of a segment or region in the storage container that is to be removed from the storage container. **Reducing the Size of a Volume or Storage Object** An EVMS volume or storage object can be comprised of one or more EVMS objects, regions, segments, or disks. Whether or not a volume or storage object can be shrunk depends upon how it is constructed. For example, if a volume consists of a single segment with no EVMS features applied to it, then whether or not you can shrink the volume depends upon whether the segment manager that created that segment can decrease the size of that segment. You can shrink a more complicated volume in several ways. For example, you can shrink a volume created from several segments using EVMS Drive Linking by decreasing the size of one of the segments being linked. You could also use EVMS Drive Linking to remove a segment from the drive link. If you could do both options to shrink the volume, we say that the volume has multiple shrink points, because there are multiple ways in which the volume can be shrunk. EVMS gives you control over how a volume is shrunk. To shrink a volume, you need to specify which shrink point to use. The same is true for storage objects. If there are two shrink points, the first would be the EVMS object created by EVMS Drive Linking. This storage object could be shrunk by removing a segment from it. The second shrink point would be the last segment used in the EVMS object formed by EVMS Drive Linking. While you might be able to shrink the other segments used to create this EVMS object, EVMS Drive Linking prohibits shrinking these segments. To find the shrink points for a storage object or volume, use the **Query Shrink Points** command. Once the shrink points for a volume or storage object are known, they can be used with this command to shrink the volume or storage object. The **Shrink** command has the following syntax: **Shrink :** *shrink-point* \[**,** *name* **=** *value*\] ... \[**,** *object*\] ... where - *shrink-point* is the name of a shrink point as provided by the **Query Shrink Points** command. - *name* is the name of an option supported by the plug-in module that controls *shrink-point*. - *value* is an acceptable value for option *name* - *object* is the name of an acceptable EVMS object, region, segment, or disk to be shrunk or removed from the volume. **Example:**\ This example assumes that you have a volume created from three segments using EVMS Drive Linking. The three segments used are sda1, sdb1, and sdc1. The EVMS object created by EVMS Drive Linking is called DL1, and the volume is called /dev/evms/Sample\_Volume. The segment sdc1 is controlled by the DOS Segment Manager (DosSegMgr), and it can be shrunk by 50 MB. The **Query** Shrink Points command returns DL1 and sdc1 as the available shrink points. Shrink the volume by 50 MB. ``` s:sdc1,size=50MB,sdc1 ``` ### TASK The **Task** command accesses functions specific to an EVMS plug-in module. The **Task** command can be used directly on an EVMS plug-in module, or it can be used on a volume, EVMS object, region, segment, or container. When used on a EVMS object, region segment, or container, the command is directed to the plug-in module that owns the EVMS object, region, segment, or container. When used on a volume, the command is directed to the File System Interface Module associated with the volume. The **Task** command has the following syntax: **Task :** *task-name* **,** *target* \[**,** *name* **=** *value*\] ... \[**,** *source*\] ... where - *task-name* is the name of the task as defined by the EVMS plug-in that is expected to perform the task. - *target* is the volume, object, region, segment, container, or plug-in that the task is to be performed on. - *name* is the name of an option accepted by the plug-in that controls the specified target. - *value* is an acceptable value for option *name*. - *source* is the name of a volume, object, region, segment to use when performing the specified task on the specified target. ### UNFORMAT The **Unformat** command destroys the filesystem within the specified volume. This process is typically completed by overwriting the metadata for the filesystem with zeros. All data on the filesystem is lost. The **Unformat** command has the following syntax: **Unformat :** *volume* where - **Unformat** can be abbreviated by the single letter **u**. - *volume* is the name of the volume whose filesystem is to be destroyed. ### UNMKFS The **Unmkfs** command destroys the filesystem within the specified volume. This process is typically completed by overwriting the metadata for the filesystem with zeros. All data on the filesystem is lost. The **Unmkfs** command has the following syntax: **Unmkfs :** *volume* where - **Unmkfs** can be abbreviated by the single letter **u**. - *volume* is the name of the volume whose filesystem is to be destroyed. ### UNMOUNT The **Unmount** command unmounts a volume. The **Unmount** command has the following syntax: **Unmount :** *volume* where - *volume* is the name of the Volume to be unmounted.