Hi Rich, I don't think anyone can say definitively how this problem resolved, but I believe that the dd command overwrote some of the disk label, as you describe below.
Your format output below looks like you relabeled the disk and maybe that was enough to resolve this problem. I have had success with just relabeling the disk in an active pool, when I accidentally trampled it with the wrong command. You could try to use zpool clear to clear the DEGRADED device. Possibly, scrub again and clear as needed. Thanks, Cindy On 07/12/12 08:33, RichTea wrote:
>How did you decide it is okay and that zfs saved you? Did you >NOT post some further progress in your recovery? I made no further recovery attempts, the pool imported cleanly after rebooting, or so i thought [1] as a zpool status showed no errors and i could read data from the drive again. On Thu, Jul 12, 2012 at 2:35 PM, Edward Ned Harvey <opensolarisisdeadlongliveopensola...@nedharvey.com <mailto:opensolarisisdeadlongliveopensola...@nedharvey.com>> wrote: > From: zfs-discuss-boun...@opensolaris.org <mailto:zfs-discuss-boun...@opensolaris.org> [mailto:zfs-discuss- <mailto:zfs-discuss-> > boun...@opensolaris.org <mailto:boun...@opensolaris.org>] On Behalf Of Jim Klimov > > Purely speculating, I might however suggest that your disk was > dedicated to the pool completely, so its last blocks contain > spare uberblocks (zpool labels) and that might help ZFS detect > and import the pool - Certain types of data have multiple copies on disk. I have overwritten the first 1MB of a disk before, and then still been able to import the pool, so I suspect, with a little effort, you'll be able to import your pool again. After the pool is imported, of course, some of your data is very likely to be corrupt. ZFS should be able to detect it, because the checksum won't match. You should run a scrub. [1] Ok i have run a scrub on the pool and is now being reported as being in DEGRADED status again. I did think it was strange that the zpool had magically recovered its self: root@n36l:~# zpool status data2 pool: data2 state: DEGRADED status: One or more devices has experienced an unrecoverable error. An attempt was made to correct the error. Applications are unaffected. action: Determine if the device needs to be replaced, and clear the errors using 'zpool clear' or replace the device with 'zpool replace'. see: http://www.sun.com/msg/ZFS-8000-9P scan: scrub repaired 0 in 0h26m with 0 errors on Thu Jul 12 15:07:47 2012 config: NAME STATE READ WRITE CKSUM data2 DEGRADED 0 0 0 c2t0d0s0 DEGRADED 0 0 0 too many errors errors: No known data errors At least it is letting me access data for now, i guess the only fix is to migrate data off and then "rebuild" the disk. -- Ritchie You'll be able to produce a list of all the partially-corrupted files. Most likely, you'll just want to rm those files, and then you'll know you have good files, whatever is still left. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
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