zfs rollback issue

I am sure this is a trivial issue, but I am not finding the answer.

I am experimenting with zfs and in particularly backing out patches or other
changes that go south.  With ufs we would break the mirror so that we could
reboot from the mirror if we needed to back out the change.  With zfs we would
like to take a snapshot of the volume and then revert back to that snapshot if
necessary

The pool on my test box is egate-pool.  It contains a mirror of two 146g
drives.

I took a zfs snapshot:
zfs snapshot egate-pool@feb24

root on cbar-test1:/# zfs list
NAME                                  USED  AVAIL  REFER  MOUNTPOINT
egate-pool                           6.46G   127G   106K  /egate-pool
egate-pool@feb24                        1K      -   106K  -
egate-pool/ROOT                      2.96G   127G    31K  legacy
egate-pool/ROOT/s10s_u10wos_17b      2.96G   127G  2.93G  /
egate-pool/ROOT/s10s_u10wos_17b/var  36.1M   127G  36.1M  /var
egate-pool/dump                      1.50G   127G  1.50G  -
egate-pool/export                      63K   127G    32K  /export
egate-pool/export/home                 31K   127G    31K  /export/home
egate-pool/swap                      2.00G   129G    16K  -
root on cbar-test1:/#

I then made a bunch of changes on the system (added users, changed shells,
added directories, etc) and then attempted to back it out:
zfs rollback egate-pool@feb24

even after a reboot there is no rollback.  There also is no error, so I do not
know what it does not like.

Christopher L. Barnard
-------------------
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