ZFS 10.1 send single snapshot - space 'used' irregularity
Rick Romero
rick at havokmon.com
Thu Apr 9 21:39:10 UTC 2015
I have 3 servers, A, B, C. I'm building C to replace A, and replicating
the data to C from backup B. A is offsite in relation to B and C.
All servers are FreeBSD 10.1, except A - which is 9.2.
I'm confused on disk usage. Not so much a GB here or there, but 250GB is
'unaccounted for' on C. C and A should be a pretty close match.
A - looks correct
sysvolssd2/home used
495G -
sysvolssd2/home usedbysnapshots
37.9G -
sysvolssd2/home usedbydataset
456G -
sysvolssd2/home usedbychildren
669M -
sysvolssd2/home usedbyrefreservation
0 -
sysvolssd2/home logicalused
585G -
NAME SIZE ALLOC FREE CAP
DEDUP HEALTH ALTROOT
sysvolssd2 1.39T 744G 680G 52%
1.00x ONLINE -
B - looks correct (backup of A, holds more snapshots and other crap than A)
sysvol/primessd_home used
777G -
sysvol/primessd_home usedbysnapshots
240G -
sysvol/primessd_home usedbydataset
537G -
sysvol/primessd_home usedbychildren
0 -
sysvol/primessd_home usedbyrefreservation
0 -
sysvol/primessd_home logicalused
754G -
NAME SIZE ALLOC FREE FRAG EXPANDSZ CAP
DEDUP HEALTH ALTROOT
sysvol 4.53T 2.43T 2.10T 20%
- 53% 1.00x ONLINE -
C - missing what appears to be the multiple snapshot data. Only the
latest snapshot was sent, not the entire dataset. So 531GB is close
enough to the 537G of B's dataset.
sysvol_enc/home used
758G -
sysvol_enc/home usedbysnapshots
3.00M -
sysvol_enc/home usedbydataset
752G -
sysvol_enc/home usedbychildren
5.84G -
sysvol_enc/home usedbyrefreservation
0 -
sysvol_enc/home logicalused
531G -
NAME SIZE ALLOC FREE FRAG EXPANDSZ CAP
DEDUP HEALTH ALTROOT
sysvol_enc 1.39T 1.12T 277G 49%
- 80% 1.00x ONLINE -
C is geli encrypted and B is not.
Unfortunately when I check another server that's geli encrypted, it looks
fine:
E -
nlsysvol/home used
13.8G -
nlsysvol/home usedbysnapshots
5.58G -
nlsysvol/home usedbydataset
7.78G -
nlsysvol/home usedbychildren
483M -
nlsysvol/home usedbyrefreservation
0 -
nlsysvol/home logicalused
12.0G -
NAME SIZE ALLOC FREE FRAG EXPANDSZ CAP
DEDUP HEALTH ALTROOT
nlsysvol 115G 42.8G 72.2G -
- 37% 1.00x ONLINE -
So the difference shouldn't be related to the encryption. It's almost as
if the send from B to C included all the incremental snapshots, but didn't
actually account for them. Am I reading this wrong, or is something else
not right ?
Should I delete that dataset, re-send the entire original dataset, then
delete the incremental snapshots?
It makes me a little concerned that deleting a snapshot might delete the
data which was written at that time, even though it was not deleted in
followup snapshots...
And I assume FRAG is fragmentation. 50% is a bit strange for a brand new
receive, isn't it?
help. :)
Rick
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