Re: [OmniOS-discuss] r151014 users - beware of illumos 6214 - steps to check and repair...
> From: Guenther Alka > Sent: Monday, September 14, 2015 9:21 AM > > 1. what is the recommended way to detect possible problems >a. run scrub? seems useless I don't think it is necessarily useless, it might detect a problem. However, from what I understand there might be a problem it doesn't detect. So it can be considered verification there is a problem, but not verification that there isn't. >b. run zdb pool and check for what I ran a basic zdb and also a 'zdb -bbccsv', the former seems to be core dumping on parsing the history, but the latter ran successfully with no issues. If I understood George correctly, 'zdb -bbccsv' should be fairly reliable on finding metadata corruption as it traverses all of the blocks. > 2. when using an L2Arc and there is no obvious error detected by scrub > or zdb >a. trash the pool and restore from backup via rsync with possible > file corruptions but ZFS structure is 100% ok then >b. keep the pool and hope that there is no metadata corruption? >c. some action to verify that at least the pool is ok: Hmm, at this point given a successful scrub and successful zdb runs I'm going to keep my fingers crossed that I have no corruption. I was only running the buggy code for it out of month, without a particularly high load, so hopefully I got lucky. > 3. when using an L2Arc and there is an error detected by scrub or zdb [...] >b. keep the pool and hope that there is no metadata corruption If the scrub or zdb detect errors, it is possible your box might panic at some point, or be unable to import the pool after a reboot. So in that case, I don't think just keeping it is advisable :). I'm not sure if there is any way to fix it or if the best case is to try to restore it or temporarily transfer the data elsewhere, re-create it, and put it back. ___ OmniOS-discuss mailing list OmniOS-discuss@lists.omniti.com http://lists.omniti.com/mailman/listinfo/omnios-discuss
Re: [OmniOS-discuss] r151014 users - beware of illumos 6214 - steps to check and repair...
What is the recommended action on OmniOS 151014 about the L2Arc Problem
1. what is the recommended way to detect possible problems
a. run scrub? seems useless
b. run zdb pool and check for what
You said: Look for assertion failures, or other non-0 exits. Is
this the key for a corrupt pool?
2. when using an L2Arc and there is no obvious error detected by scrub
or zdb
a. trash the pool and restore from backup via rsync with possible
file corruptions but ZFS structure is 100% ok then
b. keep the pool and hope that there is no metadata corruption?
c. some action to verify that at least the pool is ok:
3. when using an L2Arc and there is an error detected by scrub or zdb
a. trash the pool and restore from backup with possible file
corruption but pool is 100% ok
b. keep the pool and hope that there is no metadata corruption
c. some action to verify that at least the pool is ok:
Is there an alert page at OmniOS wiki about?
Gea
Am 10.09.2015 um 13:53 schrieb Dan McDonald:
If you are using a zpool with r151014 and you have an L2ARC ("cache") vdev, I
recommend at this time disabling it. You may disable it by uttering:
zpool remove
For example:
zpool remove data c2t2d0
The bug in question has a good analysis here:
https://www.illumos.org/issues/6214
This bug can lead to problems ranging from false-positives on zpool scrub all
the way up to actual pool corruption.
We will be updating the package repo AND the install media once 6214 is
upstreamed to illumos-gate, and pulled back into the r151014 branch of
illumos-omnios. The fix is undergoing some tests from ZFS experts right now to
verify its correctness.
So please disable your L2ARC/cache devices for maximum data safety. You can
add them back after we update r151014 by uttering:
zpool add cache
PLEASE NOTE the "cache" indicator when you add back. If you omit this, the
vdev is ADDED to your pool, an operation one can't reverse.
zpool add data cache c2t2d0
Thanks,
Dan
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