Hello.
I was wondering if the upgrade from ESX3.5 to vSphere has a time span?
Yes, and the length of it will largely depend on the size of your environment, the components involved and the amount of testing you want (or are required) to do.
I know the steps to take to make the upgrade succesfull, but can I, for instance, wait a day after every step?
I want to upgrade to vCenter and ESX4.0, but than want to wait 2 day's before I upgrade my VM's.
If a day or two days is enough time for your testing and verification processes to happen after each step, then the answer is yes. Some actions, like backups, may need to run longer or be tested prior to the normal scheduled time(s). It is really about verifying the results of each step of the upgrade as it pertains to your environment, and that will ultimately take the amount of time it takes. An upgrade for a shop with 100 hosts will certainly have a very different timeline than a shop with 2 hosts would have. As is almost always the case with virtualization, these things are rather difficult to generalize.
Is this adviceable / supported?
Developing a solid upgrade plan that includes testing scenarios for your specific environment is the best approach moving forward. It is definitely wise to do the upgrade in steps, but the time spent between these steps is somewhat irrelevant if you aren't using it for testing or verification of the upgrade.
Good Luck with the upgrade!
Brian Atkinson | vExpert | VMTN Moderator | Author of "VCP5-DCV VMware Certified Professional-Data Center Virtualization on vSphere 5.5 Study Guide: VCP-550" | @vmroyale | http://vmroyale.com
