2009-03-10.
Thanks to acquisition of a flat LCD monitor to replace the aging,
dimming and fuzzying big old Sun monitor, that old monitor and 
the Ultra60 that went with it have been removed from the work 
room.  In order to try out ZFS and its snapshots, the Ultra has
been put in the server cupboard, and just my ~nt/work directory
has been mounted from it onto the others (serv, box), with all 
the files now copied over onto the ZFS export.


# on ultra:
zpool create -m /zfs zfs /dev/dsk/c0t1d0
zfs set sharenfs=on zfs/nt
zfs set quota=4G zfs/nt
zfs set reservation=1G
svcadm enable nfs/server
chown -R nt:nt /zfs/nt/
zfs snapshot zfs/nt/work@2009-03-10_02:36:45
[this snapshot worked: the directory /zfs/nt/work/.zfs appeared 
 just when asked for, not when the directory was listed]

# in /etc/zfs_bkps.sh on ultra:
/usr/sbin/zfs snapshot "zfs/nt/work@`date +%F_%H%M%S`"

# in crontab on ultra:
00,10,20,30,40,50 * * * * /etc/zfs_bkps.sh

# in fstab on box:
ultra:/zfs/nt/work      /home/nt/work   nfs rw,tcp,intr,hard,nfsvers=3      0 0

# from df -h on box:
serv:/srv/home        881G  784G   88G  90% /home
ultra:/zfs/nt/work    4.0G  256M  3.8G   7% /home/nt/work

# from ll ~ on box (note the `+' -- ACL entries by default)
drwxr-xr-x+  13 nt nt   14 2009-02-25 23:09 work
# from getfacl work on box:
# ---
# file: work
# owner: nt
# group: nt
user::rwx
group::r-x
mask::rwx
other::r-x
# ---


As of the next day, it's working nicely: a snapshot every 10 minutes,
and very little space taken up by them.

The following gives a list of all snapshots, including incremental
space used, and total size of snapshot:
zfs list -H -t snapshot

A particular snapshot can be removed with e.g.
zfs destroy zfs/nt/work@2009-03-10_074000