Migrating storage when VM has multiple datastores

[LesBarnes]

How can I (or can I) use Storage vMotion on ESX4.0 U1 to migrate a portion of a VM to a new datastore? I have a VM with 5 datastores attached and need to move 1of the datastores to a larger sized LUN. What's the best method?

[Troy_Clavell]

That's a good question, and I do not think you can do this through the GUI svmoiton in vSphere4, but hey, since i've never tried it, i can't say for sure.

you can use the old fashion method and do it throught the CLI

http://www.vmware.com/pdf/vi3_35/esx_3/r35u2/vi3_35_25_u2_rcli.pdf

[LesBarnes]

I found the answer.... (actually VMware tech support told me about it -- I had another trouble ticket open and got a 2-fer )

In vCenter choose Migrate --> Change datastore --> select Advanced button --> select **, then dropdown box -- choose new datastore --> continue Next until Finish.

This will let you move 1, or multiple individual datastores, or the location of the virtual machine .vmx configuration file.

In a related subject, I learned the virtual machine .vmx file should be located on the datastore with the largest block size if the virtual machine has multiple defined datastores. Otherwise, VM snapshots may fail as the .vmdk files get larger. In my case, I had a VM with 4 datastores associated with it -- 3 x 100GB datastores have a 1MB block size while the 4th is a 1.2TB volume with an 8MB block size. The VM .vmx file was located on one of the 1MB block size datastores so snapshots would fail. Migrating the .vmx file to the 1.2TB volume fixed the snapshot issue. And, I learned how to migrate individual datastores.

[BigHug · Accepted solution]

On the "select datastore" windows, click on "advanced" button. Then you can specify the location of each VMDK and configuration files.