mfi (Dell H700) + hot swapping doesn't appear to work with RC1

[Jan Mikkelsen]

On 15/12/2011, at 2:16 AM, Borja Marcos wrote:

> 
> On Dec 14, 2011, at 2:09 PM, Hugo Silva wrote:
> 
>> Hello,
>> 
>> First of all apologies if this has been fixed in RC3. I set this server
>> up with mfsbsd, which is RC1, and didn't get to update the system yet.
>> 
>> This box has 6 hdds, a 2-mirror zpool was set up as the root pool, with
>> 2 spares.
>> 
>> While testing hot swapping I noticed that while the controller detects
>> disk removal/insertion, the zpool will never recover. The problem seems
>> to be deeper than ZFS, as disklabel/fdisk/etc also fail on the
>> removed-and-reinserted disk.
>> 
>> At the ZFS level, doing a zpool clear yields more errors on the removed
>> disk; rebooting becomes the only option to make the pool healthy again.
>> 
>> 
>> Is this normal? Did I miss any step?
> 
> I assume that you have tried to use the H700 as a "JBOD" card, defining logical volume for each hard disk.
> 
> The problem is: that gorgeous, fantastic, masterful, Nobel award candidate card, has a wonderful behavior in that case. If you extract one of the disks, the logical volume associated to it is invalidated. So, you insert a replacement disk, and the card refuses to recognize the volume. What is even worse, in order to recover it's mandatory to reboot the complete system *AND* go through the RAID configuration utility.
> 
> That's the problem. The card refuses  to work as a simple disk controller without frills, and the frills get in the way.
> 
> To summarize: it isn't FreeBSD's fault, no matter which version you use. It's a "feature" coming directly from the geniuses who designed the card.

Hugo: You missed a step. Borja: No reboot required.

For the mfi controllers I have been testing recently (MegaRAID 9261-8i), you need to install the sysutils/megacli port, and use that to clear the "foreignness" of the disk you just added. Something like:

    MegaCli -CfgForeign -Clear -a0

You should be able to then recreate it as a JBOD device, and progress through whatever higher level recovery you need to do.

Regards,

Jan Mikkelsen