FreeBSD 11 and Perc H720P Mini raid controller

Author: Solène

Date: 25 May 2016

Tags: freebsd11 hardware

NILI had a problem with my 3 latests R430 Dell server which all have a

PERC H730P Mini raid controller. The installer could barely works and

slowly, and 2 servers were booting and crashing with FS corruption

while the latest just didn't boot and the raid was cleared.

It is a problem with a driver of the raid controller. I don't

understand exatly the problem but I found a fix.

From man page mfi(4)

A tunable is provided to adjust the mfi 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 mfi.

In order to install the system, you have to set

**hw.mfi.mrsas_enable=1** on the install media, and set this on the

installed system before booting it.

There are two ways for that:

- if you use a usb media, you can mount it and edit /boot/loader.conf

and add `hw.mfi.mrsas_enable=1`

- at the boot screen with the logo freebsd, choose **3) Espace to boot

prompt**, type `set hw.mfi.mrsas_enable=1` and **boot**

You will have to edit /boot/loader.conf to add the line on the

installed system from the live system of the installer.

I have been struggling a long before understanding the problem. I hope

this message could save time to somebody else.