Last night/this morning we upgraded our production Zimbra system from 5.0.18 to 6.0.4, unfortunately not without some drama. So first, I have to give extraordinary kudos to Irfan at Zimbra who worked with us through the wee hours to get our system functional for end users before the sun came up this morning.
To be fair, our system has been in production since 4.0.3, and though we have been doing a lot of testing prior to this upgrade, this was probably the least smooth major version upgrade we have had with Zimbra. Not complaining mind you; having headed a multi-million dollar software development project I am of the strong opinion that Zimbra's QA is very, very good. These things happen, so I thought it would be helpful to post here some of what we are seeing. We have a support ticket open with Zimbra on these issues.
First, the upgrade installer destroyed the GoDaddy commercial certs, which needed to get reinstalled. But since the certificate directories have changed a little versus the documentation we were using, we started getting a little nervous following the documentation until we sorted that out. This seems to be a common problem, so we were prepared.
Second, we use syslog-ng on SLES10 SP3, and the upgrade installer broke that (thanks Irfan for fixing that one).
Third, even after syslogging was fixed, the Admin Console functionality remains diminished. We have no "Certificates" tab in the left-hand nav bar, and the Server Status has all red "X"s. The License tab under Servers > Global Settings has also gone missing, so we'll need to use the CLI to replace our soon-to-be-expiring ZCS license. I expect we will find a few more broken bits in the coming days.
Fourth, LDAP replication was totally broken by this upgrade (and at this point remains broken). Our additional MTA and mailbox servers, which were originally LDAP replicas for performance, now talk to the LDAP master directly. Zimbra support has escalated this issue for us. This error seems to have impacted one other poster in the forums too:
LDAP / Replication on 5.x -> 6.x Upgrade
Fifth, we are discovering as the day unfolds a few non-mission critical differences between 5.0 and 6.0 that cause confusion for end users. For example, it used to be that if you had a COS on a domain and an account which had the Documents feature enabled but where domain-level Documents had not been created, then when users logged in, the Documents tab simply would not display. Under 6.0.4, the Documents tab
does display, and when users click on the Documents tab they get a jetty 500 error -- and call us. It's as if the COS settings now have new preferences over the domain settings, which now requires us to add a few more COSs. Not a big deal for sure, but some end users get very nervous over errors like these--more so the ones who have Apache experience!
Overall, nothing really show-stopping here; we keep enough spare horsepower on our servers so that our LDAP master is perfectly capable of handling the load until Zimbra figures out the issue. And again, Zimbra support has been really, really terrific.
But if you are considering upgrading a ZCS system which has been in production as long as ours, at least from our experience it appears that the upgrade to 6.0.x may not be without some bumps in the road.
Hope that helps,
Mark