Why I love ZFS

No silent data corruption because of a checksum on each block, copy on write means no fsck EVER (it does not even have one), no RAID5 write hole, add disks to the pool on the fly, put volumes there as well as filesystems and export them via iSCSI or NFS, quotas, compression and it is easy to use. Check it out here, or watch this video

It is so easy to use, here is my command line session when adding 4 disks to my array. Took me perhaps 5 minutes and its worth noting that there was no pause between issuing each command as its all pretty much instant. I had to import the pool at the beginning as I had just installed OpenSolaris developer edition to see if it was any better than Nexenta (it was not). The spacing of the output is a little off, but hopefully its still understandable.

# zfs list
no datasets available
# zpool import Toms
cannot import 'Toms': pool may be in use from other system
use '-f' to import anyway
# zpool import -f Toms
# zfs list
NAME                      USED  AVAIL  REFER  MOUNTPOINT
Toms                     1.33T  9.84G  40.4K  none
Toms/500G                 723G  9.84G   723G  /share/500G
Toms/Notes               25.9G  9.84G  25.9G  /share/Notes
Toms/files               25.6G  9.84G  25.6G  /share/files
Toms/share                532G  9.84G  46.4K  /share
Toms/share/SetupFiles    72.2G  9.84G  72.2G  /share/SetupFiles
Toms/share/TalkingBooks   139G  9.84G   139G  /share/TalkingBooks
Toms/share/Tunes         57.5G  9.84G  57.5G  /share/Tunes
Toms/share/Videos         263G  9.84G   263G  /share/Videos
Toms/share/apps           159M  9.84G   159M  /share/apps
Toms/share/downloads     26.9K  9.84G  26.9K  /share/downloads
Toms/xbox                50.7G  9.84G  50.7G  /share/xbox

# zpool status
pool: Toms
state: ONLINE
status: The pool is formatted using an older on-disk format.  The pool can
still be used, but some features are unavailable.
action: Upgrade the pool using 'zpool upgrade'.  Once this is done, the
pool will no longer be accessible on older software versions.
scrub: none requested
config:

NAME        STATE     READ WRITE CKSUM
Toms        ONLINE       0     0     0
raidz1      ONLINE       0     0     0
c2t3d0      ONLINE       0     0     0
c2t0d0      ONLINE       0     0     0
c2t2d0      ONLINE       0     0     0
c2t1d0      ONLINE       0     0     0

errors: No known data errors

# zpool add Toms raidz c2t4d0 c2t5d0 c2t6d0 c2t7d0
invalid vdev specification
use '-f' to override the following errors:
/dev/dsk/c2t4d0s0 is part of exported or potentially active ZFS pool
mypool. Please see zpool(1M).
# zpool add -f Toms raidz c2t4d0 c2t5d0 c2t6d0 c2t7d0
# zpool status
pool: Toms
state: ONLINE
status: The pool is formatted using an older on-disk format.  The pool can
still be used, but some features are unavailable.
action: Upgrade the pool using 'zpool upgrade'.  Once this is done, the
pool will no longer be accessible on older software versions.
scrub: none requested
config:

NAME        STATE     READ WRITE CKSUM
Toms        ONLINE       0     0     0
raidz1    ONLINE       0     0     0
c2t3d0  ONLINE       0     0     0
c2t0d0  ONLINE       0     0     0
c2t2d0  ONLINE       0     0     0
c2t1d0  ONLINE       0     0     0
raidz1    ONLINE       0     0     0
c2t4d0  ONLINE       0     0     0
c2t5d0  ONLINE       0     0     0
c2t6d0  ONLINE       0     0     0
c2t7d0  ONLINE       0     0     0

errors: No known data errors
# zfs list
NAME                      USED  AVAIL  REFER  MOUNTPOINT
Toms                     1.33T   888G  40.4K  none
Toms/500G                 723G   888G   723G  /share/500G
Toms/Notes               25.9G   888G  25.9G  /share/Notes
Toms/files               25.6G   888G  25.6G  /share/files
Toms/share                532G   888G  46.4K  /share
Toms/share/SetupFiles    72.2G   888G  72.2G  /share/SetupFiles
Toms/share/TalkingBooks   139G   888G   139G  /share/TalkingBooks
Toms/share/Tunes         57.5G   888G  57.5G  /share/Tunes
Toms/share/Videos         263G   888G   263G  /share/Videos
Toms/share/apps           159M   888G   159M  /share/apps
Toms/share/downloads     26.9K   888G  26.9K  /share/downloads
Toms/xbox                50.7G   888G  50.7G  /share/xbox
# zpool upgrade Toms
This system is currently running ZFS pool version 8.

Successfully upgraded 'Toms' from version 7 to version 8