zfs snapshot rollback rpool question

Hi!

running Solaris 10

[2020-09-08 09:08:10] root@ls-sol-lb4dbe2:/ # uname -a

SunOS ls-sol-lb4dbe2 5.10 Generic_150401-59 i86pc i386 i86pc

given one rpool (actually a Vsphere node) and I want to snapshot the whole rpool.

But when I test this, eg. by creating a file in /etc, the rollback doesn't revert my changes.

[2020-09-08 09:05:29] root@ls-sol-lb4dbe2:/ # zpool list

NAME    SIZE  ALLOC   FREE  CAP  HEALTH  ALTROOT

rpool  49.8G  13.7G  36.0G  27%  ONLINE  -

[2020-09-08 09:12:48] root@ls-sol-lb4dbe2:/ # zfs list

NAME                                USED  AVAIL  REFER  MOUNTPOINT

rpool                              16.9G  32.1G  42.5K  /rpool
rpool/ROOT                         3.25G  32.1G    31K  legacy

rpool/ROOT/s10x_u11wos_24a         3.25G  32.1G  3.24G  /