I am looking for the least amount of down time to do the following:

Issue: One ESX Host running ESXi 4.0 (locally attached storage) with one VM running on it. This host needs to be updated to ESXi 5.1 in the least amount of down time for the running VM.

Possible solutions:

1) Use a temporary server install ESXi 5.1, bring it up on the same network, export the VM to an OVF. Import OVF into Temp ESXi 5.1 server, then upgrade ESXi 4.0 to 5.1, then move the VM off the Temp Host to the new 5.1 host. (not sure if I can export from 4.0, then import to 5.1, any one know?)

2) Use a Temporary Server to install ESXi 5.1 and create a cluster. Add the ESXi 4.0 server, cold migrate single VM. Upgrade ESXi 4.0 to ESX 5.1, cold Migrarte VM back.

3) Export VM, Do an in place Upgrade of ESXi 4.0 to ESX 5.1.


If anyone has experience with how long any of these options (or any options that work better ) please let me know.


VMWare outlines this very clearly, as you've noted.

Download new ISO containing the ESXi 5.1 distribution. Burn it to CD. Insert into your powered-off server, boot and run the installer.

This method preserves your existing VMFS datastore and works without a hitch.

Trying to move your VM's off, exporting and all of that other stuff introduces many more potential failure points than just running the supported in-place installer process.

Once updated, you will want to update your virtual machine hardware version and the VMWare guest tools for each VM.


ovf import/export should work in general. however, if you could avoid inplace upgrade, you should always install 5.1 cleanly. i find far fewer problems with clean install (although i have not specifically done from 4.0 -> 5.1, only 4.0/4.1 -> 5.0, but it should be similar).

if you do have an additional server, you can create a cluster, but then you would have to install a vcenter to do migration, as standalone esxi does not support migration, only import/export, or some sort of file copying. in any case, an additional sever would help a lot because you can verify that your vms actually work fine after upgrade.

also, you do not specify what is the guestOS of your vms. in general linux vms migrate much easier than windows, as the latter is quite sensitive to any hw change, whether virtual or physical, and sometimes you just have to rebuild.

  • He said he was using local storage so vmotion (if that's what you mean by migrate) wouldn't be an option unfortunatly – Rqomey Nov 20 '12 at 12:04
  • not true at all, migration is possible with local storage, but just more restricted, such as no live migration from local to local without a virtual san appliance, for instance. have you tried it? i have migrate from/to local storage numerous times. – johnshen64 Nov 20 '12 at 16:06
  • Sorry, for some reason I was thinking of live migration! My bad, you are right. – Rqomey Nov 21 '12 at 8:21

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