mfi(4) LSI MegaRAID SAS driver


To compile this driver into the kernel, place the following lines in your kernel configuration file:
device pci device mfi

Alternatively, to load the driver as a module at boot time, place the following line in loader.conf5:



This driver is for LSI's next generation PCI Express SAS RAID controllers. Access to RAID arrays (logical disks) from this driver is provided via /dev/mfid? device nodes. A simple management interface is also provided on a per-controller basis via the /dev/mfi? device node.

The name is derived from the phrase "MegaRAID Firmware Interface", which is substantially different than the old "MegaRAID" interface and thus requires a new driver. Older SCSI and SATA MegaRAID cards are supported by amr(4) and will not work with this driver.

Two sysctls are provided to tune the driver's behavior when a request is made to remove a mounted volume. By default the driver will disallow any requests to remove a mounted volume. If the sysctl dev.mfi.%d.delete_busy_volumes is set to 1, then the driver will allow mounted volumes to be removed.

A tunable is provided to adjust the driver's behaviour when attaching to a card. By default the driver will attach to all known cards with high probe priority. If the tunable hw.mfi.mrsas_enable is set to 1, then the driver will reduce its probe priority to allow mrsas to attach to the card instead of .


The driver supports the following hardware:

  • LSI MegaRAID SAS 1078
  • LSI MegaRAID SAS 8408E
  • LSI MegaRAID SAS 8480E
  • LSI MegaRAID SAS 9240
  • LSI MegaRAID SAS 9260
  • Dell PERC5
  • Dell PERC6
  • IBM ServeRAID M1015 SAS/SATA
  • IBM ServeRAID M1115 SAS/SATA
  • IBM ServeRAID M5015 SAS/SATA
  • IBM ServeRAID M5110 SAS/SATA
  • IBM ServeRAID-MR10i
  • Intel RAID Controller SRCSAS18E
  • Intel RAID Controller SROMBSAS18E


array/logical disk interface
management interface


"mfid%d: Unable to delete busy device"
An attempt was made to remove a mounted volume.


The driver first appeared in Fx 6.1 .


The driver and this manual page were written by An Scott Long Aq [email protected] .


The driver does not support big-endian architectures at this time.