If you like to keep your OS and data vmdk seperate like I do and you did not do so during
initial VM creation you still have a few options to seperate out your disks.
One of them would be to perform a cold migration. This will allow you to change the storage
for your vmdk. By default it will drop the all files into one destination but you have the option
to store each vmdk in its purpose dedicated LUN by selecting the advanced button.
This works great but there are times where it is not practicle to shutdown your VM.
This is where storage vmotion comes in. We will be making use of the svmotion plugin from lost creations.
In this example we want to move a VM with two disk, one for OS and one for Data, and store the disks
in an appropriatly configured LUN. In ESX3.5, moving individual vmdks is not supported but there is a work around,
albeit a bit long.
Drag your entire VM to the Data LUN and click apply. This will take a wee while to complete depending on the size
of your disks. Once completed, drag the entire VM to the OS LUN but do not click apply! Select your Data disk and drag it back
to the Data LUN. Click apply. The vmx and os.vmdk will be moved again but the data.vmdk stays put.
Another way that works is to use RCLI and enter the following command.
H:\svmotion.pl --server vmcenter --username allblack --password xxxxxxx --vm
"[old_DS] vm1/vm1.vmx:new_DS" --disks="[old_DS] vm1/vm1.vmdk:old_DS"
The example above copies over the vmx file and all disks except my vm1.vmdk disk as specified with the --disks parameter.