--- name: "drbdmeta-9.0" section: "8" platform: "linux" package: "drbd-utils" version: "9.22.0-1.1" release: "Debian 13 (Trixie)" platforms: ["linux"] url: "https://new.carta.tech/drbdmeta-9.0" --- # drbdmeta-9.0(8) Manipulate the DRBD on-disk metadata ## NAME drbdmeta - Manipulate the DRBD on-disk metadata ## SYNOPSIS **drbdmeta** \[--force\] \[--ignore-sanity-checks\] {*device*} {v06 *minor* \| v07 *meta\_dev index* \| v08 *meta\_dev index* \| v09 *meta\_dev index*} {*command*} \[*cmd args*...\] ## DESCRIPTION The **drbdmeta** utility is used for creating, displaying, and modifying DRBD's on-disk metadata. Users usually interact with the **drbdadm** utility, which provides a more high-level interface to DRBD than **drbdmeta**. (See **drbdadm**'s **--dry-run** option to see how **drbdadm** uses **drbdmeta**.) This utility can only be used on devices which are not currently in use by the kernel. The first argument (*device*) specifies the drbd device associated with a volume, or “-” if no device is associated with that volume. If the drbd device is specified, the **drbdmeta** utility makes sure that the drbd device does not currently have a volume attached to prevent meta-data of an active volume from being destroyed. The second argument specifies the metadata version to use (v06, v07, v08, v09). In most metadata versions, the third argument (*meta\_dev*) specifies the device which contains the metadata; this argument can be the same as *device*. The fourth argument (*index*) can be one of the keywords **internal** (for internal metadata), **flex-internal** (in v07 for variable-sized metadata; v07 otherwise defaults to fixed-size internal metadata), **flex-external** (for variable-sized external metadata), or a numeric matadata index (for fixed-size external metadata). See the **meta-disk** parameter in [**drbd.conf**(5)](/drbd.conf/5.md). ## OPTIONS - \--force Assume yes as the answer to all questions drbdmeta would ask. - \--ignore-sanity-checks Normally, **drbdmeta** performs some sanity checks before writing to the metadata device: for example, if the device appears to contain a file system, it refuses to destroy the file system by writing into it. Use this option to ignore these checks. ## COMMANDS **create-md** \[**--peer-max-bio-size=***val*\] (metadata versions v06, v07, and v08), \ **create-md** {number-of-bitmap-slots} \[**--peer-max-bio-size=***val*\] \[**--initialize-bitmap-mode=***{automatic\|zeroout\|pwrite\|skip}*\] \[**--al-stripes=***val*\] \[**--al-stripe-size-kB=***val*\] (metadata version v09) Initialize the metadata. This is necessary before a DRBD resource can be attached. If **drbdmeta** finds an older version of DRBD metadata on the device, it asks if the format should be converted. When **drbdadm** calls **drbdmeta**'s **create-md** command for a device, it sets the *number-of-bitmap-slots* argument to the number of peers in the resource. To reserve additional bitmap slots (which allows to add more peers in the future), call **drbdmeta** directly instead. When a device is used before being connected to its peers the first time, DRBD assumes that peers can only handle 4 KiB requests by default. The **--peer-max-bio-size** option allows to set more optimistic values; use this if the versions of DRBD that this device will connect to are known. DRBD supports a maximum bio size of 32 KiB since version 8.3.8, of 128 KiB since version 8.3.9, and of 1 MiB since version 8.4.0. By default, we explicitly initialize the bitmap area to all zero. With **--initialize-bitmap-mode** you can chose to only try the fast method (**zeroout**, try ioctl BLKZEROOUT only), only use explicit **pwrite** calls, or **skip** this bitmap initialization phase completely. If you intend to do an initial full sync anyways, you can use **skip** to leave the bitmap initialization to the kernel. This can make a noticable difference when initializing huge volumes. Default is **automatic**, which is zeroout with an implicit fallback to pwrite. If you want to use more than 6433 activity log extents, or live on top of a spriped RAID, you may specify the number of stripes (**--al-stripes**, default 1), and the stripe size (**--al-stripe-size-kB**, default 32). To just use a larger linear on-disk ring-buffer, leave the number of stripes at 1, and increase the size only: **drbdmeta 0 v08 /dev/vg23/lv42 internal create-md --al-stripe-size 1M** To avoid a single "spindle" from becoming a bottleneck, increase the number of stripes, to achieve an interleaved layout of the on-disk activity-log transactions. What you give as "stripe-size" should be what is a.k.a. "chunk size" or "granularity" or "strip unit": the minimum skip to the next "spindle". **drbdmeta 0 v08 /dev/vg23/lv42 internal create-md --al-stripes 7 --al-stripe-size 64** **get-gi** \[**--node-id=***id*\] Show the data generation identifiers for a device on a particular connection. DRBD version 9.0.0 and beyond support multiple peers; use the *node-id* option to define which peer's data generation identifiers to show. **show-gi** \[**--node-id=***id*\] Similar to **get-gi**, but with explanatory information. **dump-md** Dump the metadata of a device in text form, including the bitmap and activity log. **outdate** Mark the data on a lower-level device as outdated. See [**drbdsetup**(8)](/drbdsetup/8.md) for details. **dstate** Show the current disk state of a lower-level device. **check-resize** Examine the device size of a lower-level device and its last known device size (saved in **/var/lib/drbd/drbd-minor-***minor***.lkbd** by **drbdsetup check-resize**). For internal metadata, if the size of the lower-level device has changed and the metadata can be found at the previous position, move the metadata to the new position at the end of the block device. **apply-al** Apply the activity log of the specified device. This is necessary before the device can be attached by the kernel again. ## EXPERT COMMANDS The **drbdmeta** utility can be used to fine tune metdata. Please note that this can lead to destroyed metadata or even silent data corruption; use with great care only. **set-gi** *gi* \[**--node-id=***id*\] Set the generation identifiers. The *gi* argument is a generation counter for the v06 and v07 formats, and a set of UUIDs for v08 and beyond. Accepts the same syntax as in the **get-gi** output. DRBD version 9.0.0 and beyond support multiple peers; use the *--node-id* option to define which peer's data generation identifiers to set. **restore-md** *dump\_file* Replace the metadata on the device with the contents of *dump\_file*. The dump file format is defined by the output of the **dump-md** command. ## VERSION This document was revised for version 9.0.0 of the DRBD distribution. ## AUTHOR Written by Philipp Reisner \ and Lars Ellenberg \. ## REPORTING BUGS Report bugs to \. ## COPYRIGHT Copyright 2001-2008,2012 LINBIT Information Technologies, Philipp Reisner, Lars Ellenberg. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. ## SEE ALSO [**drbdadm**(8)](/drbdadm/8.md) [**drbd.conf**(5)](/drbd.conf/5.md)