Freebsd – How to discover current time-zone (FreeNAS shell)

1. list all users?

pw usershow -a

2. change multiple users to nogroup primary group?

There's a hundred different ways to do this... I would:

foreach u ("list" "of" "users")
    pw usermod -n $u -g NewPrimaryGroup
end

You could even get the list of users from a subcommand, like pw groupshow OldGroupName | sed -e "s/.*://" -e "s/,/\ /"

3. add secondary/auxiliary groups to multiple users?

Again, a few ways to do this...

If you know the full list of secondary groups that the users should be in:

pw usermod -n UserName -G "Secondary Group List"

If you don't know the full list, or just want to add users to a group:

pw groupmod -n SecondaryGroup -m NewUserName

And removing is similairly

pw groupmod -n SecondaryGroup -d OldUserName

Basically I need to change all the users that are currently in the clients group to nogroup and add clients as an auxiliary group to them.

foreach u (`pw groupshow clients | sed -e "s/.*://" -e "s/,/\ /"`)
    pw usermod $u -g nogroup
    pw groupmod clients -m $u
end

(The above snippet is untested, but looks good after 3 seconds of double-checking, also written for csh as that's FreeBSD's default shell for users)

Here is how I would approach it, purely using FreeNAS GUI:

• Set up periodic snapshot task for a recursive snapshot from your root dataset (e.g. volume x)
• Use temp drive to create as a simple 1-disk stripe volume, say, volume y.
• Establish replication to that drive, x to y.
• Wait before replication is done.
• Set up periodic snapshot task for a recursive snapshot of y.
• Destroy and re-create x.
• Set up replication back from y to x.
• Wait before replication is done.
• Destroy y.

Disclaimer: I haven't tested this to make sure all the jails will still work, so you may want to get a confirmation from somewhere else or just be prepared to recreate jails (or carefully examine y after first replication is done). This worked smoothly for regular datasets with all historical snapshot information.