Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

We're planing to have two SQL servers updated by synchronous database mirroring. This will include a third environment configured as a witness server.

For standard windows patching - what order should we patch / reboot the servers?

share|improve this question

1 Answer 1

up vote 5 down vote accepted

The order would go like this:

  1. Update the secondary server (the one that is not currently serving connections)
  2. After it reboots, do a controlled mirroring failover to it
  3. Update the primary server (which at this point is no longer serving connections)
  4. After it reboots, you can do a controlled failover back to it if you want, but you don't have to. You can leave the connections running on the secondary box.
share|improve this answer
    
Thanks Brent, how does patching the witness server fit in? –  SuperCoolMoss May 18 '09 at 11:39
    
If the witness server isn't involved in anything else whatsoever, then you can do that first. I usually see the witness being involved with other SQL Server activities, though - for example, it might be a mirroring partner for another primary server, so it can't be rebooted willy-nilly. If you're lucky enough to have a dedicated mirroring witness that does nothing else, then you can get it done first, but it doesn't matter whether it's first or last. –  Brent Ozar May 18 '09 at 11:49
1  
Be careful just leaving the connections running on the secondary box if you don't have a license for it. It's only free if you fail back to the original principal within 45 days. –  Paul Randal May 18 '09 at 14:20
    
Great point, +1 on the comment. Didn't know about the 45-day limitation - I thought it'd be even shorter than that. –  Brent Ozar May 18 '09 at 14:24
    
Thanks Paul and Brent - Am I correct in thinking if all user databases are failed over to the secondary (no active connections to user databases on primary) then the 45 day limitation can be ignored? –  SuperCoolMoss May 18 '09 at 17:47

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.