LSI Embedded MegaRAID

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Old LSI Embedded MegaRAID and Embedded RAID-II are fakeraid controllers. Historically they was only supported by proprietary driver named megasr, available only as RPM for RHEL with kernels 2.6.18.x. Luckily most functions of megasr unofficially supported by opensource mptsas driver.

No Warranty notice

Since in this guide we use undocumented and unofficial features of mptsas drivers, there is NO WARRANTY of proper work of fakeraid. Please, before any actions on actual data perform backup first!

(Unofficial) supported cards

This list is not complete.

Name (as shown in lspci) PCI ID
LSI MegaRAID SAS 8208XLP 1000:0055
M1064E MegaRAID SAS 1000:0057
MegaRAID SAS 8208ELP/8208ELP 1000:0059

Make mptsas to support controller

By default mptsas no handles with megasr-compatible controllers. You need to provide corresponding PCI ID. First let's find out it:

root #lspci -nn
08:00.0 SCSI storage controller [0100]: LSI Logic / Symbios Logic M1064E MegaRAID SAS [1000:0057] (rev 04)

In this example PCI ID is 1000:0057. Give it to mpt-sas:

root #modprobe mptsas
root #echo "1000 0057" > /sys/bus/pci/drivers/mptsas/new_id

Now, if all goes right, your disks will be appear in system (check dmesg). For permanent effect you need add mptsas to /etc/modules.d and 'echo "1000 0057" > /sys/bus/pci/drivers/mptsas/new_id' to /etc/local.d/mptsas.start:

root #echo 'echo "1000 0057" > /sys/bus/pci/drivers/mptsas/new_id' > /etc/local.d/mptsas.start
root #chmod 755 /etc/local.d/mptsas.start

RAID capabilities

If RAID already configured in firmware and you need access to filesystem on it, you'll need to prepare your system as described here and install sys-fs/mdadm package. mdadm daemon will automatically take RAID configuration and provide it to system as /dev/mdX block device. At first time mdadm will start resynchronization, that OK.