[rescue] Solaris ZFS questions

[Patrick Giagnocavo]

On 1/12/2011 3:20 PM, John Lengeling wrote:
> I have a degraded zfs pool reporting permanent errors under Solaris 10.
> I was going to backup the existing data, destroy/create the pool and
> then restore the data.  I have a couple of questions.
> 
> 1. I believe that the degraded drive had a read-error.  When I take this
> drive out of the pool, how can I verify that I can read/write all
> sectors?
>

Can you post the relevant part of "zpool status -xv" ?

1. You can use "format" to have the drive non-destructively check.

> 2. I tried to back up the data on the pool using GnuTAR with the
> --ignore-failed-read and GnuTar still errored/exited out and didn't just
> skip the file and continue writing.   How can I get around this as I
> thought that the ignore failed read would just skip the file and
> continue on.

2. Dunno, you could try the sun-supplied tar or cpio and see what that does.

> 3. Does ZFS automatically perform a periodic read/verify scan over the
> entire pool or does this need to be enabled?

3. This is handled with "zpool scrub $POOLNAME" and can be set up in
cron, but you have to do that yourself.  If you are doing a lot of
reading/writing of data it may not be needed very often, since the
checksums are checked on each read and write.  For home users or
archival use, you want to do it more often as you may not be touching
files on a regular basis.

--Patrick