We have a 100G ZVOL on a FreeBSD 10.0-CURRENT host which claims to use 176G of disk space:
root@storage01:~ # zfs get all zroot/DATA/vtest
NAME PROPERTY VALUE SOURCE
zroot/DATA/vtest type volume -
zroot/DATA/vtest creation Fri May 24 20:44 2013 -
zroot/DATA/vtest used 176G -
zroot/DATA/vtest available 10.4T -
zroot/DATA/vtest referenced 176G -
zroot/DATA/vtest compressratio 1.00x -
zroot/DATA/vtest reservation none default
zroot/DATA/vtest volsize 100G local
zroot/DATA/vtest volblocksize 8K -
zroot/DATA/vtest checksum fletcher4 inherited from zroot
zroot/DATA/vtest compression off default
zroot/DATA/vtest readonly off default
zroot/DATA/vtest copies 1 default
zroot/DATA/vtest refreservation none local
zroot/DATA/vtest primarycache all default
zroot/DATA/vtest secondarycache all default
zroot/DATA/vtest usedbysnapshots 0 -
zroot/DATA/vtest usedbydataset 176G -
zroot/DATA/vtest usedbychildren 0 -
zroot/DATA/vtest usedbyrefreservation 0 -
zroot/DATA/vtest logbias latency default
zroot/DATA/vtest dedup off default
zroot/DATA/vtest mlslabel -
zroot/DATA/vtest sync standard default
zroot/DATA/vtest refcompressratio 1.00x -
zroot/DATA/vtest written 176G -
zroot/DATA/vtest logicalused 87.2G -
zroot/DATA/vtest logicalreferenced 87.2G -
root@storage01:~ #
This looks like a bug, how can it consume more than its volsize
if it does not have snapshots, reservations and children? Or maybe we are missing something?
Upd:
Results of zpool status -v
:
root@storage01:~ # zpool status -v
pool: zroot
state: ONLINE
scan: scrub repaired 0 in 0h6m with 0 errors on Thu May 30 05:45:11 2013
config:
NAME STATE READ WRITE CKSUM
zroot ONLINE 0 0 0
raidz2-0 ONLINE 0 0 0
gpt/disk0 ONLINE 0 0 0
gpt/disk1 ONLINE 0 0 0
gpt/disk2 ONLINE 0 0 0
gpt/disk3 ONLINE 0 0 0
gpt/disk4 ONLINE 0 0 0
gpt/disk5 ONLINE 0 0 0
cache
ada0s2 ONLINE 0 0 0
errors: No known data errors
root@storage01:~ #
Results of zpool list
:
root@storage01:~ # zpool list
NAME SIZE ALLOC FREE CAP DEDUP HEALTH ALTROOT
zroot 16.2T 288G 16.0T 1% 1.05x ONLINE -
root@storage01:~ #
Results of zfs list
:
root@storage01:~ # zfs list
NAME USED AVAIL REFER MOUNTPOINT
zroot 237G 10.4T 288K /
zroot/DATA 227G 10.4T 352K /DATA
zroot/DATA/NFS 288K 10.4T 288K /DATA/NFS
zroot/DATA/hv 10.3G 10.4T 288K /DATA/hv
zroot/DATA/hv/hv001 10.3G 10.4T 144K -
zroot/DATA/test 288K 10.4T 288K /DATA/test
zroot/DATA/vimage 41.3G 10.4T 288K /DATA/vimage
zroot/DATA/vimage/vimage_001 41.3G 10.5T 6.47G -
zroot/DATA/vtest 176G 10.4T 176G -
zroot/SYS 9.78G 10.4T 288K /SYS
zroot/SYS/ROOT 854M 10.4T 854M /
zroot/SYS/home 3.67G 10.4T 3.67G /home
zroot/SYS/tmp 352K 10.4T 352K /tmp
zroot/SYS/usr 4.78G 10.4T 427M /usr
zroot/SYS/usr/local 288K 10.4T 288K /usr/local
zroot/SYS/usr/obj 3.50G 10.4T 3.50G /usr/obj
zroot/SYS/usr/ports 895K 10.4T 320K /usr/ports
zroot/SYS/usr/ports/distfiles 288K 10.4T 288K /usr/ports/distfiles
zroot/SYS/usr/ports/packages 288K 10.4T 288K /usr/ports/packages
zroot/SYS/usr/src 887M 10.4T 887M /usr/src
zroot/SYS/var 511M 10.4T 1.78M /var
zroot/SYS/var/crash 505M 10.4T 505M /var/crash
zroot/SYS/var/db 1.71M 10.4T 1.43M /var/db
zroot/SYS/var/db/pkg 288K 10.4T 288K /var/db/pkg
zroot/SYS/var/empty 288K 10.4T 288K /var/empty
zroot/SYS/var/log 647K 10.4T 647K /var/log
zroot/SYS/var/mail 296K 10.4T 296K /var/mail
zroot/SYS/var/run 448K 10.4T 448K /var/run
zroot/SYS/var/tmp 304K 10.4T 304K /var/tmp
root@storage01:~ #
Upd 2:
We created a number of ZVOLs with different parameters and used dd
to move the content. We noticed another odd thing, disk usage was normal for ZVOLs with 16k and 128k volblocksize
and it remained abnormal for a ZVOL with 8k volblocksize
even after dd
(so this is not a fragmentation issue):
root@storage01:~ # zfs get all zroot/DATA/vtest-3
NAME PROPERTY VALUE SOURCE
zroot/DATA/vtest-3 type volume -
zroot/DATA/vtest-3 creation Fri May 31 7:35 2013 -
zroot/DATA/vtest-3 used 201G -
zroot/DATA/vtest-3 available 10.2T -
zroot/DATA/vtest-3 referenced 201G -
zroot/DATA/vtest-3 compressratio 1.00x -
zroot/DATA/vtest-3 reservation none default
zroot/DATA/vtest-3 volsize 100G local
zroot/DATA/vtest-3 volblocksize 8K -
zroot/DATA/vtest-3 checksum fletcher4 inherited from zroot
zroot/DATA/vtest-3 compression off default
zroot/DATA/vtest-3 readonly off default
zroot/DATA/vtest-3 copies 1 default
zroot/DATA/vtest-3 refreservation 103G local
zroot/DATA/vtest-3 primarycache all default
zroot/DATA/vtest-3 secondarycache all default
zroot/DATA/vtest-3 usedbysnapshots 0 -
zroot/DATA/vtest-3 usedbydataset 201G -
zroot/DATA/vtest-3 usedbychildren 0 -
zroot/DATA/vtest-3 usedbyrefreservation 0 -
zroot/DATA/vtest-3 logbias latency default
zroot/DATA/vtest-3 dedup off default
zroot/DATA/vtest-3 mlslabel -
zroot/DATA/vtest-3 sync standard default
zroot/DATA/vtest-3 refcompressratio 1.00x -
zroot/DATA/vtest-3 written 201G -
zroot/DATA/vtest-3 logicalused 100G -
zroot/DATA/vtest-3 logicalreferenced 100G -
root@storage01:~ #
and
root@storage01:~ # zfs get all zroot/DATA/vtest-16
NAME PROPERTY VALUE SOURCE
zroot/DATA/vtest-16 type volume -
zroot/DATA/vtest-16 creation Fri May 31 8:03 2013 -
zroot/DATA/vtest-16 used 102G -
zroot/DATA/vtest-16 available 10.2T -
zroot/DATA/vtest-16 referenced 101G -
zroot/DATA/vtest-16 compressratio 1.00x -
zroot/DATA/vtest-16 reservation none default
zroot/DATA/vtest-16 volsize 100G local
zroot/DATA/vtest-16 volblocksize 16K -
zroot/DATA/vtest-16 checksum fletcher4 inherited from zroot
zroot/DATA/vtest-16 compression off default
zroot/DATA/vtest-16 readonly off default
zroot/DATA/vtest-16 copies 1 default
zroot/DATA/vtest-16 refreservation 102G local
zroot/DATA/vtest-16 primarycache all default
zroot/DATA/vtest-16 secondarycache all default
zroot/DATA/vtest-16 usedbysnapshots 0 -
zroot/DATA/vtest-16 usedbydataset 101G -
zroot/DATA/vtest-16 usedbychildren 0 -
zroot/DATA/vtest-16 usedbyrefreservation 886M -
zroot/DATA/vtest-16 logbias latency default
zroot/DATA/vtest-16 dedup off default
zroot/DATA/vtest-16 mlslabel -
zroot/DATA/vtest-16 sync standard default
zroot/DATA/vtest-16 refcompressratio 1.00x -
zroot/DATA/vtest-16 written 101G -
zroot/DATA/vtest-16 logicalused 100G -
zroot/DATA/vtest-16 logicalreferenced 100G -
root@storage01:~ #