rollback a destroyed filesystem

[Li, Yee-Ting]

hi, long story short: i managed to nuke a filesystem (almost the entire pool!) when doing a send/recv, and i would like to recover it. reading around suggests to use "zdb -hh" and "zdb -lu" to find a TXG that might be at the point before the 'oh sh*t' moment and then run "zpool import -T <txg>".

so my basic question is: given that i do *not* see the txg that i would like to roll back to in the "zdb -lu" output, can i still roll back? i know that there are 127 uberblocks, but i only see 32 in the output. just for reference i would like to roll back to 368706, but the current one reported is 369026.

when i try a reimport, i get the following:

$ zpool import -f -T 368706 -m -F -d /dev/disk/by-id tank
cannot import 'tank': one or more devices is currently unavailable

$ zpool import
pool: tank
id: 13219489813523663703
state: ONLINE
action: The pool can be imported using its name or numeric identifier.
config:
tank ONLINE
raidz1-0 ONLINE
ata-HGST_HDS5C4040ALE630_PL2331LAGJGG5J ONLINE
ata-Hitachi_HDS5C4040ALE630_PL1321LAGAPPUH ONLINE
ata-Hitachi_HDS5C4040ALE630_PL1321LAGAPT4H ONLINE
ata-WDC_WD20EADS-00S2B0_WD-WCAVY0992435 ONLINE
ata-WDC_WD20EARX-00PASB0_WD-WMAZA5413633 ONLINE
raidz1-3 ONLINE
ata-WDC_WD10EADS-00L5B1_WD-WCAU45648979 ONLINE
ata-WDC_WD10EACS-32ZJB0_WD-WCASJ0248848 ONLINE
ata-WDC_WD20EARS-00S8B1_WD-WCAVY2851098 ONLINE
ata-WDC_WD20EADS-00R6B0_WD-WCAVY0221974 ONLINE
ata-WDC_WD20EARX-00PASB0_WD-WMAZA6948199 ONLINE
cache
scsi-3500000e118fc3340
scsi-3500000e118fc42e0
logs
scsi-3500000e118ed9b30 ONLINE
scsi-3500000e118fc3bc0 ONLINE




any help is much appreciated!

[Andrew Gabriel]

Post by Li, Yee-Ting
hi, long story short: i managed to nuke a filesystem (almost the entire pool!) when doing a send/recv, and i would like to recover it. reading around suggests to use "zdb -hh" and "zdb -lu" to find a TXG that might be at the point before the 'oh sh*t' moment and then run "zpool import -T <txg>".
so my basic question is: given that i do *not* see the txg that i would like to roll back to in the "zdb -lu" output, can i still roll back? i know that there are 127 uberblocks, but i only see 32 in the output.

I think there are only 32 uberblock slots if you are using ashift=12 (4k
blocksize).

[Yee-Ting Li]

Post by Andrew Gabriel
I think there are only 32 uberblock slots if you are using ashift=12 (4k
blocksize).

thanks Andrew: does that mean that i'm sh*t-out-of-luck? cheers,