--- name: "mrsas" section: "4freebsd" platform: "linux" package: "freebsd-manpages" version: "12.2-2" release: "Debian 13 (Trixie)" platforms: ["linux"] url: "https://new.carta.tech/mrsas/4freebsd" --- # mrsas(4freebsd) LSI MegaRAID 6Gb/s and 12Gb/s SAS+SATA RAID controller driver ## NAME **mrsas** – LSI MegaRAID 6Gb/s and 12Gb/s SAS+SATA RAID controller driver ## SYNOPSIS To compile this driver into the kernel, place the following lines in your kernel configuration file: **device pci** **device mrsas** Alternatively, to load the driver as a module at boot time, place the following line in [loader.conf(5)](/loader.conf/5.md): ``` mrsas_load="YES" ``` ## DESCRIPTION The **mrsas** driver will detect LSI's next generation (6Gb/s and 12Gb/s) PCI Express SAS/SATA RAID controllers. See the **HARDWARE** section for the supported devices list. A disk (virtual disk/physical disk) attached to the **mrsas** driver will be visible to the user through [camcontrol(8)](/camcontrol/8.md) as */dev/da?* device nodes. A simple management interface is also provided on a per-controller basis via the */dev/mrsas?* device node. The **mrsas** name is derived from the phrase "MegaRAID SAS HBA", which is substantially different than the old "MegaRAID" Driver [mfi(4)](/mfi/4.md) which does not connect targets to the [cam(4)](/cam/4.md) layer and thus requires a new driver which attaches targets to the [cam(4)](/cam/4.md) layer. Older MegaRAID controllers are supported by [mfi(4)](/mfi/4.md) and will not work with **mrsas**, but both the [mfi(4)](/mfi/4.md) and **mrsas** drivers can detect and manage the LSI MegaRAID SAS 2208/2308/3008/3108 series of controllers. The [device.hints(5)](/device.hints/5.md) option is provided to tune the **mrsas** driver's behavior for LSI MegaRAID SAS 2208/2308/3008/3108 controllers. By default, the [mfi(4)](/mfi/4.md) driver will detect these controllers. See the **PRIORITY** section to know more about driver priority for MR-Fusion devices. **mrsas** will provide a priority of (-30) (between BUS\_PROBE\_DEFAULT and BUS\_PROBE\_LOW\_PRIORITY) at probe call for device id's 0x005B, 0x005D, and 0x005F so that **mrsas** does not take control of these devices without user intervention. Solid-state drives (SSD) get ATA TRIM support with **mrsas** if underlying adapter allows it. This may require configuring SSD as Non-RAID drive rather then JBOD virtual mode. ## HARDWARE The **mrsas** driver supports the following hardware: \[ Thunderbolt 6Gb/s MR controller \] - LSI MegaRAID SAS 9265 - LSI MegaRAID SAS 9266 - LSI MegaRAID SAS 9267 - LSI MegaRAID SAS 9270 - LSI MegaRAID SAS 9271 - LSI MegaRAID SAS 9272 - LSI MegaRAID SAS 9285 - LSI MegaRAID SAS 9286 - DELL PERC H810 - DELL PERC H710/P \[ Invader/Fury 12Gb/s MR controller \] - LSI MegaRAID SAS 9380 - LSI MegaRAID SAS 9361 - LSI MegaRAID SAS 9341 - DELL PERC H830 - DELL PERC H730/P - DELL PERC H330 ## CONFIGURATION To disable Online Controller Reset(OCR) for a specific **mrsas** driver instance, set the following tunable value in [loader.conf(5)](/loader.conf/5.md): ``` dev.mrsas.X.disable_ocr=1 ``` where X is the adapter number. To change the I/O timeout value for a specific **mrsas** driver instance, set the following tunable value in [loader.conf(5)](/loader.conf/5.md): ``` dev.mrsas.X.mrsas_io_timeout=NNNNNN ``` where NNNNNN is the timeout value in milli-seconds. To change the firmware fault check timer value for a specific **mrsas** driver instance, set the following tunable value in [loader.conf(5)](/loader.conf/5.md): ``` dev.mrsas.X.mrsas_fw_fault_check_delay=NN ``` where NN is the fault check delay value in seconds. The current number of active I/O commands is shown in the *dev.mrsas.X.fw\_outstanding* [sysctl(8)](/sysctl/8.md) variable. ## DEBUGGING To enable debugging prints from the **mrsas** driver, set the *hw.mrsas.X.debug\_level* variable, where X is the adapter number, either in [loader.conf(5)](/loader.conf/5.md) or via [sysctl(8)](/sysctl/8.md). The following bits have the described effects: - 0x01 Enable informational prints. - 0x02 Enable tracing prints. - 0x04 Enable prints for driver faults. - 0x08 Enable prints for OCR and I/O timeout. - 0x10 Enable prints for AEN events. ## PRIORITY The **mrsas** driver will always set a default (-30) priority in the PCI subsystem for selection of MR-Fusion cards. (It is between BUS\_PROBE\_DEFAULT and BUS\_PROBE\_LOW\_PRIORITY). MR-Fusion Controllers include all cards with the Device IDs - 0x005B, 0x005D, 0x005F. The [mfi(4)](/mfi/4.md) driver will set a priority of either BUS\_PROBE\_DEFAULT or BUS\_PROBE\_LOW\_PRIORITY (depending on the device.hints setting) in the PCI subsystem for selection of MR-Fusion cards. With the above design in place, the [mfi(4)](/mfi/4.md) driver will attach to a MR-Fusion card given that it has a higher priority than **mrsas**. Using */boot/device.hints* (as mentioned below), the user can provide a preference for the **mrsas** driver to detect a MR-Fusion card instead of the [mfi(4)](/mfi/4.md) driver. **hw.mfi.mrsas\_enable="1"** At boot time, the [mfi(4)](/mfi/4.md) driver will get priority to detect MR-Fusion controllers by default. Before changing this default driver selection policy, LSI advises users to understand how the driver selection policy works. LSI's policy is to provide priority to the [mfi(4)](/mfi/4.md) driver to detect MR-Fusion cards, but allow for the ability to choose the **mrsas** driver to detect MR-Fusion cards. LSI recommends setting hw.mfi.mrsas\_enable="0" for customers who are using the older [mfi(4)](/mfi/4.md) driver and do not want to switch to **mrsas**. For those customers who are using a MR-Fusion controller for the first time, LSI recommends using the **mrsas** driver and setting hw.mfi.mrsas\_enable="1". Changing the default behavior is well tested under most conditions, but unexpected behavior may pop up if more complex and unrealistic operations are executed by switching between the [mfi(4)](/mfi/4.md) and **mrsas** drivers for MR-Fusion. Switching drivers is designed to happen only one time. Although multiple switching is possible, it is not recommended. The user should decide from **Start** **of** **Day** which driver they want to use for the MR-Fusion card. The user may see different device names when switching from [mfi(4)](/mfi/4.md) to **mrsas**. This behavior is **Functions** **As** **Designed** and the user needs to change the [fstab(5)](/fstab/5.md) entry manually if they are doing any experiments with [mfi(4)](/mfi/4.md) and **mrsas** interoperability. ## FILES - */dev/da?* array/logical disk interface - */dev/mrsas?* management interface ## SEE ALSO [cam(4)](/cam/4.md), [mfi(4)](/mfi/4.md), [pci(4)](/pci/4.md), [device.hints(5)](/device.hints/5.md), [camcontrol(8)](/camcontrol/8.md) ## HISTORY The **mrsas** driver first appeared in FreeBSD 10.1. **mfi Driver:** [mfi(4)](/mfi/4.md) is the old FreeBSD driver which started with support for Gen-1 Controllers and was extended to support up to MR-Fusion (Device ID = 0x005B, 0x005D, 0x005F). **mrsas Driver:** **mrsas** is the new driver reworked by LSI which supports Thunderbolt and onward products. The SAS+SATA RAID controller with device id 0x005b is referred to as the Thunderbolt controller throughout this man page. **cam** **aware** **HBA** **drivers:** FreeBSD has a [cam(4)](/cam/4.md) layer which attaches storage devices and provides a common access mechanism to storage controllers and attached devices. The **mrsas** driver is [cam(4)](/cam/4.md) aware and devices associated with **mrsas** can be seen using [camcontrol(8)](/camcontrol/8.md). The [mfi(4)](/mfi/4.md) driver does not understand the [cam(4)](/cam/4.md) layer and it directly associates storage disks to the block layer. **Thunderbolt** **Controller:** This is the 6Gb/s MegaRAID HBA card which has device id 0x005B. **Invader** **Controller:** This is 12Gb/s MegaRAID HBA card which has device id 0x005D. **Fury** **Controller:** This is the 12Gb/s MegaRAID HBA card which has device id 0x005F. ## AUTHORS The **mrsas** driver and this manual page were written by Kashyap Desai ⟨*Kashyap.Desai@lsi.com*⟩. ## TODO The driver does not support big-endian architectures at this time. The driver does not support alias for device name (it is required when the user switches between two drivers and does not want to edit */etc/fstab* manually). The **mrsas** driver exposes devices as */dev/da?*, whereas [mfi(4)](/mfi/4.md) exposes devices as */dev/mfid?*. **mrsas** does not support the Linux Emulator interface. **mrsas** will not work with [mfiutil(8)](/mfiutil/8.md).