how to import raidz2, if only one disk is missing?

Wed May 25 03:23:57 UTC 2011

Vladislav,

Hi. Just a heads up on this instead of waiting for the MFC to happen you
may want to boot mfsBSD from Martin Matuska [1][2] to check your disks
ahead of time and diagnose whether it is worthwhile waiting for the MFC.

Recently another fellow IRC'er had a ZFSv15 pool on 8.2-X and had one
drive faulted that needed to be replaced. These drives were moved from
one machine to another and the drive that faulted was unrecoverable for
whatever reason, but unknown to the user, he had a second drive in the
new machine that was showing up with some massive DMA errors after a
reboot making the total drives that were faulted and irreparable
greater than the amount that is allowed to be faulted in a raidz1 pool
ultimately making his whole pool unrecoverable. Unfortunately he ended
up having to destroy the pool and live with the loss of data.

Anyway to cut to the facts of that. Only one of the faulted drives were
picked up by ZFS v15 "don't know why" and the one with all the DMA
errors only shown up in v28 as faulted which I found to be quite odd.

It would be to your advantage to run some drive tests using smartctl or
whatever your comfortable with and also grab one of the v28 images below
to test boot and try repairing while waiting.

Good luck.

1). http://mfsbsd.vx.sk/iso/mfsbsd-8.2-zfsv28-i386.iso
2). http://mfsbsd.vx.sk/iso/mfsbsd-8.2-zfsv28-amd64.iso

On Tue, May 24, 2011 at 11:18:23PM +0300, Vladislav V. Prodan wrote:
> 24.05.2011 23:11, Pawel Jakub Dawidek wrote:
> > Which FreeBSD version and ZFS version are you running? If this is v15,
> > then you might need 9-CURRENT to import that pool or wait for MFC of
> > v28, which should happen soon.
> 
> FreeBSD 8.2-STABLE #0: Wed Apr 20 03:20:47 EEST 2011 
> vlad11 at beastie.mydomain.local:/usr/obj/usr/src/sys/otrada.1  amd64
> 
> Yes, thank you, wait for MFC.
> For a 9-CURRENT serious slowdown in the speed of SATA drives.
> 

-- 

 Regards, (jhell)
 Jason Hellenthal

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