Information requst re: ESXi 7.x import to PVE 8.3.3

Mr_Trees

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Feb 22, 2025
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I am one of the (possible) flood of former ESXi users, who will not doubt be asking questions here during their migration attempts. I have my PVE setup, zfs, working zpools and most of my virtual machines imported from ESXi, I have one VM that is particularly large, and it is on its way to my PVE during this week.

Whilst setting up the import, I did not get a chance to choose what format the new disks on the PVE would be (greyed out), so they are all heading into what I presume is the right place, a zpool I called rust02 and in the "rust02 (pve)" pool i see the disks (slowly) arriving - they are listed as "raw" in their format collumn, so i believe are "fat" disks - they are showing up in /dev/zvol/rust02 as their names, each one is showing up as two parts, one i guess the device and one the partition with hard links ../../zd224 and ../../zd224p1.

I am unwilling to try and modify anything at the moment, as the largest disk is still on its way, however, once the VM has finished its import, I would like to convert the disks with their content intact to a format that is "thin", perhaps Qcow2?

I have enough spare pool capacity in another zpool, but I have been unable so far to work out what I need to do to convert/migrate the raw /dev/zd224 or more probably /dev/zd224p1 disk into a Qcow2 disk in my rust01 zpool. Should I just be treating them as "real" disks to convert?

I would welcome any pointers at this point as I do not want to take a wrong direction at this early point in my PVE induction/journey; on a related note, as a long time Deb Linux user, I am SO impressed with what i can do already with PVE, I just wish I had been pushed off the VSphere cliff a little earlier.
 
I would like to convert the disks with their content intact to a format that is "thin", perhaps Qcow2?
ZFS is already thin (or sparse) as it does not store empty/zero blocks (unless you chose the ZFS storage to not be thin but that can easily be changed on the command line for existing virtual disks). You might need to explicitly trim the disks inside the VM.
 
Thanks @leesteken - I have just realised that I did not click the "thin" tick box when I created the zpools... can I select that retrospectively and is there anything i need to do to refactor the disks to thin?
 
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I have just realised that I did not click the "thin" tick box when I created them... can I select that retrospectively and is there anything i need to do to refactor the disks to thin?/
New virtual disks will be thin but not existing ones. Fortunately, all virtual disks on ZFS are thin/sparse but the non-thin ones are counted as if they use the full space. Simply unset the refreservation for existing virtual disks: https://forum.proxmox.com/threads/thin-provision-after-the-fact.132568/#post-583272
 
@leesteken - thanks, that is exactly what I needed to know, the disks from now on will be created as "thin" (no reservation) and with the refreservation flag and the correct tick box i think i am good, but will have to wait till the 8tb arrives before working with the VM