ZFS on Hardware RAID

[andy thomas]

On Sun, 20 Jan 2019, Ireneusz Pluta wrote:

> W dniu 2019-01-20 o?09:45, andy thomas pisze:
>> I run a number of very busy webservers (Dell PowerEdge 2950 with LSI 
>> MegaRAID SAS 1078 controllers) with the first two disks in RAID 1 as the 
>> FreeBSD system disk and the remaining 4 disks configured as RAID 0 virtual 
>> disks making up a ZFS RAIDz1 pool with 3 disks plus one hot spare. 
> In this configuration, have you ever made a test of causing a drive failure, 
> to see the hot spare activated?

No haven't tried this as the clients never gave me the time to try out 
possible failure secenarios on the 2950 servers. But I now have a spare 
2950 with the same RAID controller as the production servers so I could 
try that asearly as tomorrow & report back.

But I do know a Dell T710 server with Perc 6/i controller and all 8 disks 
configured as RAID 0 with 5 of them in a ZFS RAIDz1 pool plus one spare, 
a failed disk can be detached and replaced with the spare using zpool 
command & the pool resilvered manually. (This was on FBSD 9.3 whose ZFS 
version 28 I don't think supported automatic activation of hot spares). 
Resilvering took a long time, about 2.5 days, as these were 1 TB Western 
Digital Caviar Black disks but it was successful.

Andy