Academic exercise: trying to recover a corrupted pool
Borja Marcos
borjam at sarenet.es
Mon Jan 8 14:31:44 UTC 2018
Hi,
ONLY AS AN ACADEMIC EXERCISE, WARNING :)
I have a broken ZFS pool and I’m wondering wether it should be readable. The pool was made with four
apparently troublesome OCZ SSD drives pulled from other systems. They are connected to a LSI2008 adapter.
The pool was created as a raidz2, so it’s supposed to survive the loss of two drives. It has lost two of them
and I am unable to import it.
I have lost no useful data, I was using it just for testing. Now it has become an interesting study subject though :)
Any ideas? I have tried to recover even doing the “radical thing” (zdb -Z -AAA -e -p /dev poolname). No success.
Again, I am just curious.
Thanks!
Borja.
Now, the data
If I try to recover it using zdb -e -X I get this:
# zdb -e -X cashopul
Configuration for import:
vdev_children: 1
version: 5000
pool_guid: 585029935900186516
name: 'cashopul'
state: 0
hostid: 605799378
hostname: ''
vdev_tree:
type: 'root'
id: 0
guid: 585029935900186516
children[0]:
type: 'raidz'
id: 0
guid: 17478362601057626606
nparity: 2
metaslab_array: 40
metaslab_shift: 34
ashift: 12
asize: 2048421527552
is_log: 0
create_txg: 4
children[0]:
type: 'disk'
id: 0
guid: 5865132871942380009
path: '/dev/da2'
whole_disk: 1
not_present: 1
DTL: 10392
create_txg: 4
children[1]:
type: 'disk'
id: 1
guid: 17151294206067279763
path: '/dev/da2'
whole_disk: 1
DTL: 10391
create_txg: 4
children[2]:
type: 'disk'
id: 2
guid: 4780356075228908448
whole_disk: 1
DTL: 10390
create_txg: 4
path: '/dev/da2'
children[3]:
type: 'disk'
id: 3
guid: 4182482849823292334
whole_disk: 1
DTL: 10389
create_txg: 4
path: '/dev/da3'
zdb: can't open 'cashopul': Device not configured
ZFS_DBGMSG(zdb):
Reading the individual labels of the surviving drives,
# zdb -l /dev/da2
------------------------------------
LABEL 0
------------------------------------
version: 5000
name: 'cashopul'
state: 0
txg: 26855087
pool_guid: 585029935900186516
hostid: 605799378
hostname: ''
top_guid: 17478362601057626606
guid: 4780356075228908448
vdev_children: 1
vdev_tree:
type: 'raidz'
id: 0
guid: 17478362601057626606
nparity: 2
metaslab_array: 40
metaslab_shift: 34
ashift: 12
asize: 2048421527552
is_log: 0
create_txg: 4
children[0]:
type: 'disk'
id: 0
guid: 5865132871942380009
path: '/dev/da2'
whole_disk: 1
not_present: 1
DTL: 10392
create_txg: 4
children[1]:
type: 'disk'
id: 1
guid: 17151294206067279763
path: '/dev/da2'
whole_disk: 1
DTL: 10391
create_txg: 4
children[2]:
type: 'disk'
id: 2
guid: 4780356075228908448
path: '/dev/da3'
whole_disk: 1
DTL: 10390
create_txg: 4
children[3]:
type: 'disk'
id: 3
guid: 4182482849823292334
path: '/dev/da4'
whole_disk: 1
DTL: 10389
create_txg: 4
features_for_read:
com.delphix:hole_birth
com.delphix:embedded_data
------------------------------------
LABEL 1
------------------------------------
version: 5000
name: 'cashopul'
state: 0
txg: 26855087
pool_guid: 585029935900186516
hostid: 605799378
hostname: ''
top_guid: 17478362601057626606
guid: 4780356075228908448
vdev_children: 1
vdev_tree:
type: 'raidz'
id: 0
guid: 17478362601057626606
nparity: 2
metaslab_array: 40
metaslab_shift: 34
ashift: 12
asize: 2048421527552
is_log: 0
create_txg: 4
children[0]:
type: 'disk'
id: 0
guid: 5865132871942380009
path: '/dev/da2'
whole_disk: 1
not_present: 1
DTL: 10392
create_txg: 4
children[1]:
type: 'disk'
id: 1
guid: 17151294206067279763
path: '/dev/da2'
whole_disk: 1
DTL: 10391
create_txg: 4
children[2]:
type: 'disk'
id: 2
guid: 4780356075228908448
path: '/dev/da3'
whole_disk: 1
DTL: 10390
create_txg: 4
children[3]:
type: 'disk'
id: 3
guid: 4182482849823292334
path: '/dev/da4'
whole_disk: 1
DTL: 10389
create_txg: 4
features_for_read:
com.delphix:hole_birth
com.delphix:embedded_data
------------------------------------
LABEL 2
------------------------------------
version: 5000
name: 'cashopul'
state: 0
txg: 26855087
pool_guid: 585029935900186516
hostid: 605799378
hostname: ''
top_guid: 17478362601057626606
guid: 4780356075228908448
vdev_children: 1
vdev_tree:
type: 'raidz'
id: 0
guid: 17478362601057626606
nparity: 2
metaslab_array: 40
metaslab_shift: 34
ashift: 12
asize: 2048421527552
is_log: 0
create_txg: 4
children[0]:
type: 'disk'
id: 0
guid: 5865132871942380009
path: '/dev/da2'
whole_disk: 1
not_present: 1
DTL: 10392
create_txg: 4
children[1]:
type: 'disk'
id: 1
guid: 17151294206067279763
path: '/dev/da2'
whole_disk: 1
DTL: 10391
create_txg: 4
children[2]:
type: 'disk'
id: 2
guid: 4780356075228908448
path: '/dev/da3'
whole_disk: 1
DTL: 10390
create_txg: 4
children[3]:
type: 'disk'
id: 3
guid: 4182482849823292334
path: '/dev/da4'
whole_disk: 1
DTL: 10389
create_txg: 4
features_for_read:
com.delphix:hole_birth
com.delphix:embedded_data
------------------------------------
LABEL 3
------------------------------------
version: 5000
name: 'cashopul'
state: 0
txg: 26855087
pool_guid: 585029935900186516
hostid: 605799378
hostname: ''
top_guid: 17478362601057626606
guid: 4780356075228908448
vdev_children: 1
vdev_tree:
type: 'raidz'
id: 0
guid: 17478362601057626606
nparity: 2
metaslab_array: 40
metaslab_shift: 34
ashift: 12
asize: 2048421527552
is_log: 0
create_txg: 4
children[0]:
type: 'disk'
id: 0
guid: 5865132871942380009
path: '/dev/da2'
whole_disk: 1
not_present: 1
DTL: 10392
create_txg: 4
children[1]:
type: 'disk'
id: 1
guid: 17151294206067279763
path: '/dev/da2'
whole_disk: 1
DTL: 10391
create_txg: 4
children[2]:
type: 'disk'
id: 2
guid: 4780356075228908448
path: '/dev/da3'
whole_disk: 1
DTL: 10390
create_txg: 4
children[3]:
type: 'disk'
id: 3
guid: 4182482849823292334
path: '/dev/da4'
whole_disk: 1
DTL: 10389
create_txg: 4
features_for_read:
com.delphix:hole_birth
com.delphix:embedded_data
# zdb -l /dev/da3
------------------------------------
LABEL 0
------------------------------------
version: 5000
name: 'cashopul'
state: 0
txg: 26855087
pool_guid: 585029935900186516
hostid: 605799378
hostname: ''
top_guid: 17478362601057626606
guid: 4182482849823292334
vdev_children: 1
vdev_tree:
type: 'raidz'
id: 0
guid: 17478362601057626606
nparity: 2
metaslab_array: 40
metaslab_shift: 34
ashift: 12
asize: 2048421527552
is_log: 0
create_txg: 4
children[0]:
type: 'disk'
id: 0
guid: 5865132871942380009
path: '/dev/da2'
whole_disk: 1
not_present: 1
DTL: 10392
create_txg: 4
children[1]:
type: 'disk'
id: 1
guid: 17151294206067279763
path: '/dev/da2'
whole_disk: 1
DTL: 10391
create_txg: 4
children[2]:
type: 'disk'
id: 2
guid: 4780356075228908448
path: '/dev/da3'
whole_disk: 1
DTL: 10390
create_txg: 4
children[3]:
type: 'disk'
id: 3
guid: 4182482849823292334
path: '/dev/da4'
whole_disk: 1
DTL: 10389
create_txg: 4
features_for_read:
com.delphix:hole_birth
com.delphix:embedded_data
------------------------------------
LABEL 1
------------------------------------
version: 5000
name: 'cashopul'
state: 0
txg: 26855087
pool_guid: 585029935900186516
hostid: 605799378
hostname: ''
top_guid: 17478362601057626606
guid: 4182482849823292334
vdev_children: 1
vdev_tree:
type: 'raidz'
id: 0
guid: 17478362601057626606
nparity: 2
metaslab_array: 40
metaslab_shift: 34
ashift: 12
asize: 2048421527552
is_log: 0
create_txg: 4
children[0]:
type: 'disk'
id: 0
guid: 5865132871942380009
path: '/dev/da2'
whole_disk: 1
not_present: 1
DTL: 10392
create_txg: 4
children[1]:
type: 'disk'
id: 1
guid: 17151294206067279763
path: '/dev/da2'
whole_disk: 1
DTL: 10391
create_txg: 4
children[2]:
type: 'disk'
id: 2
guid: 4780356075228908448
path: '/dev/da3'
whole_disk: 1
DTL: 10390
create_txg: 4
children[3]:
type: 'disk'
id: 3
guid: 4182482849823292334
path: '/dev/da4'
whole_disk: 1
DTL: 10389
create_txg: 4
features_for_read:
com.delphix:hole_birth
com.delphix:embedded_data
------------------------------------
LABEL 2
------------------------------------
version: 5000
name: 'cashopul'
state: 0
txg: 26855087
pool_guid: 585029935900186516
hostid: 605799378
hostname: ''
top_guid: 17478362601057626606
guid: 4182482849823292334
vdev_children: 1
vdev_tree:
type: 'raidz'
id: 0
guid: 17478362601057626606
nparity: 2
metaslab_array: 40
metaslab_shift: 34
ashift: 12
asize: 2048421527552
is_log: 0
create_txg: 4
children[0]:
type: 'disk'
id: 0
guid: 5865132871942380009
path: '/dev/da2'
whole_disk: 1
not_present: 1
DTL: 10392
create_txg: 4
children[1]:
type: 'disk'
id: 1
guid: 17151294206067279763
path: '/dev/da2'
whole_disk: 1
DTL: 10391
create_txg: 4
children[2]:
type: 'disk'
id: 2
guid: 4780356075228908448
path: '/dev/da3'
whole_disk: 1
DTL: 10390
create_txg: 4
children[3]:
type: 'disk'
id: 3
guid: 4182482849823292334
path: '/dev/da4'
whole_disk: 1
DTL: 10389
create_txg: 4
features_for_read:
com.delphix:hole_birth
com.delphix:embedded_data
------------------------------------
LABEL 3
------------------------------------
version: 5000
name: 'cashopul'
state: 0
txg: 26855087
pool_guid: 585029935900186516
hostid: 605799378
hostname: ''
top_guid: 17478362601057626606
guid: 4182482849823292334
vdev_children: 1
vdev_tree:
type: 'raidz'
id: 0
guid: 17478362601057626606
nparity: 2
metaslab_array: 40
metaslab_shift: 34
ashift: 12
asize: 2048421527552
is_log: 0
create_txg: 4
children[0]:
type: 'disk'
id: 0
guid: 5865132871942380009
path: '/dev/da2'
whole_disk: 1
not_present: 1
DTL: 10392
create_txg: 4
children[1]:
type: 'disk'
id: 1
guid: 17151294206067279763
path: '/dev/da2'
whole_disk: 1
DTL: 10391
create_txg: 4
children[2]:
type: 'disk'
id: 2
guid: 4780356075228908448
path: '/dev/da3'
whole_disk: 1
DTL: 10390
create_txg: 4
children[3]:
type: 'disk'
id: 3
guid: 4182482849823292334
path: '/dev/da4'
whole_disk: 1
DTL: 10389
create_txg: 4
features_for_read:
com.delphix:hole_birth
com.delphix:embedded_data
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