Thanks both for your reply. Lucky we have custombuild to assist us in those matters.
I remember doing an update a few years back, and all mail arrived in queue, but wasn't delivered to the mailboxes any further. So I didn't wan't to break it a second time
If there any many updates, I personally try to do small batches of updated at once, and check if everything still works in between.
And of course make sure there's a good backup to fall back on if all might be Fubarred...
I make just before from some important databases a dump together with backup of apllications that connect to them to be sure they are in "synch". ( is much easier to restore and.. then)
Then a snapshot of server / vps
And yes if many/more in smaller amounts testing in between.
And YES i needed snapshot backup and those databases BACKUP ONCE OR TWO TIMES. over more then 10 years now.
ok ok If only small changes in updates so as some extra in a conf file ok , i trust on the normal backups.
OYEA important try to read log files after update.