We are running a XenServer pool on an IBM BladeCenter S with 4 HS22 blades installed. 3 of the blades are in a pool and the fourth not. The blades have no internal storage and all get it from the BladeCenter san. Three of the blades have XenServer 6.5 installed. The fourth was used to see if the hardware is capable of installing 7.6 and it worked without a problem.
On a separate machine I tested the upgrade from 6.5 to 7.6 and again worked with no problems. The next step is to upgrade the pool. We cannot use running pool update as we are on the free version. I'm a little unsure about the procedure. In my mind it should work as follows; Move VM's from master to the others (just to be safe), reboot the master and do the upgrade. The master is now a different version but will still be in the pool and still the master of the pool, correct?
Next move over VM's to the master and do the upgrade on the next blade and the next etc. Am I right in assuming that? I know you cannot take the VM's to the older versions once done. Am I also correct in assuming the upgrade will not mess around with the san storage?