We are currently planning an upgrade from 5.3.0 to 6.0. Can this be considered as a minor upgrade (like 5.2 to 5.3) ? Any real-life experience already ?
Thanks in advance for any feedback !
Just about to do this myself so can't talk about real life experience other than a lab. If you haven't already the following document is very useful:
Read it and plan out your upgrade ensuring you have snapshots of the servers and backups of the database if you're using vCenter/Composer. Biggest issue I've experienced (limited though it is) has been certificates. Just make sure you've got an export of these (from the MMC) and a backup of the certificate location (again for Composer on vCenter). If the certificates do get nuked make sure you know how to re-import them.
The upgrade process for 5.3->6.0 is very similar to 5.2->5.3, but there are definitely more differences between the releases - a bunch of new features, no separate feature pack installer, several internal changes and admin UI updates, plus local mode is no longer supported. I certainly wouldn't call it a minor upgrade.
I have just done the upgrade from 5.2 to 6, and found it fairly painless apart from the SQL requirements for View Composer. I was using SQL Express 2008 R2 on my Vcenter server (only a small install of around 60 VMs and 3 hosts).
ESXi 5.5 Vcenter can use 2008 R2, but according to the upgrade notes View Composer can not use Express 2008 R2 on a 5.5 Vcenter. It can on a 5.1 host but not 5.5. So I upgraded the SQL Express first, but then being generally a bit of a amateur as far as SQL goes, I noticed after the upgrade of View that the Admin tools - Data Sources ODBC - System DSN was still pointing to the version 10 native client, not the new version 11 native client, and like a fool I decided to delete and recreate the System DSNs for both Vcenter and Composer. All seemed well until later that day when Vcenter stopped and none of the users Workstations restarted themselves as per the power options. Next Morning the users tried to login to powered off machines!!! I managed to just delete the version 11 System DSN for Vcenter, and recreate it using Native client 10, and that worked fine and allowed Vcenter manager service to start, but View composer just wouldn't work. I then tried going back to the Native client 10 DSN for that as well, but still wouldn't play. I ended up reinstalling View composer (2 stages, Remove, then re-install), but using the existing database, but missed a big point here and didn't use one of the existing certificates. I created a new default one, and got an error in Connection server, and couldn't verify the self signed default certificate. So one rollback to snapshot, uninstall and reinstall, picking one of the existing certificates, later, and all is back up and running. Users VMs all powered on and no complaints about problems. Just need to upgrade the agents on all the VMs, although the test one seems to be working ok.
Just take your time and snapshot everything before you start.