On 08/20/2012 10:15 PM, Jim Klimov wrote: > 2012-08-20 23:39, Sašo Kiselkov пишет: >>> We then tried to recreate the pool, which was successful - but >>> without data… >> >> A zpool create overwrites all labels on a device (that's why you had to >> add "-f", which essentially means "blame me if all goes wrong"). Since >> the vdev labels contain the root block pointer (which points to the root >> block of the entire pool object tree) and the value in this block >> pointer moves around as new data is added (due to COW semantics), your >> data is now toast. Sorry about that. > > As was recently discussed on the list, it is difficult to recreate > the label for the disks. Not impossible, however, but quite an > experiment - and an undocumented one AFAIK.
He described that he re-created zpool, so I take it he re-created it with all component vdevs (both the mirrored disks and the zvol), so there are no more labels left to coy. > You might be in a bit of luck, because your zvol-based component > of the pool might have some important data (last known TXG number > and address of the current three copies of the root block for ZFS > data tree). > > Assuming that you did not write much to the pool disks after that > forced creation of the new pool, recreation of labels for those > disks (or one of them since they were mirrored) should theoretically > be possible and help. Perhaps some bytes were overwritten and lost > forever in the data area of the pool during creation of the new > pool's root dataset and other structures, but most data should be > intact. If he re-created it with only the mirrored disks, then maybe. If he re-created it with all vdevs, then the data really is gone. -- Saso _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
