VM disk moved from LVM Thin to LVM Thin no longer 'thin'

[KirstyA]

I wanted to move a VM disk image on a hard disk LVM Thin volume to an SSD LVM Thin volume, because it was too slow on the hard disk.
I used the GUI Move option to move it, but once it was moved it was no longer a used space of 23GB but had expanded up to the full provisioned size of 100GB.

I moved another VM disk image a while ago and did not have this problem.
See progress of two jobs below, latest one did expand, previous one did not expand.
You can see the commands and job type are different, yet I used the same 'Move' GUI option.
Both disk images are 'raw'.

Why has it expanded and how can I move it without it expanding?

Has something changed with the command behind the 'Move' GUI option??


The one I just tried to move, (which expanded to full size), said this:-
create full clone of drive scsi0 (pmx-1_WD-BE-1TB-01:vm-101-disk-1)
Using default stripesize 64.00 KiB.
Logical volume "vm-101-disk-0" created.
drive mirror is starting for drive-scsi0
drive-scsi0: transferred: 0 bytes remaining: 107374182400 bytes total: 107374182400 bytes progression: 0.00 % busy: 1 ready: 0
drive-scsi0: transferred: 73400320 bytes remaining: 107300782080 bytes total: 107374182400 bytes progression: 0.07 % busy: 1 ready: 0
drive-scsi0: transferred: 196083712 bytes remaining: 107178098688 bytes total: 107374182400 bytes progression: 0.18 % busy: 1 ready: 0
~~~~~~
drive-scsi0: transferred: 107271421952 bytes remaining: 106364928 bytes total: 107377786880 bytes progression: 99.90 % busy: 1 ready: 0
drive-scsi0: transferred: 107375951872 bytes remaining: 1835008 bytes total: 107377786880 bytes progression: 100.00 % busy: 1 ready: 0
drive-scsi0: transferred: 107377852416 bytes remaining: 393216 bytes total: 107378245632 bytes progression: 100.00 % busy: 1 ready: 1
all mirroring jobs are ready
drive-scsi0: Completing block job...
drive-scsi0: Completed successfully.
drive-scsi0 : finished
TASK OK

The previous move, (which did not expand), said this:-
create full clone of drive scsi0 (pmx-1_WD-BE-1TB-01:vm-102-disk-1)
Using default stripesize 64.00 KiB.
For thin pool auto extension activation/thin_pool_autoextend_threshold should be below 100.
Logical volume "vm-102-disk-0" created.
transferred: 0 bytes remaining: 107374182400 bytes total: 107374182400 bytes progression: 0.00 %
transferred: 1073741824 bytes remaining: 106300440576 bytes total: 107374182400 bytes progression: 1.00 %
transferred: 2147483648 bytes remaining: 105226698752 bytes total: 107374182400 bytes progression: 2.00 %
~~~~~~
transferred: 107374182400 bytes remaining: 0 bytes total: 107374182400 bytes progression: 100.00 %
TASK OK

 

[dcsapak]

the only way i know of to correct this, is to run a fstrim afterwards inside the vm to shrink the lv again

 

[KirstyA]

Dominik, why would the 'Move' GUI option do different things when used at different times?

The latest attempt did this:-
drive mirror is starting for drive-scsi0
drive-scsi0: transferred: 0 bytes remaining: 107374182400 bytes total: 107374182400 bytes progression: 0.00 % busy: 1 ready: 0

The previous time, with a different VM disk image it did this:-
transferred: 0 bytes remaining: 107374182400 bytes total: 107374182400 bytes progression: 0.00 %

One job seems to be a 'drive mirror', the previous job was a 'transfer', from the same GUI option 'Move'
Why would it be different?
What is the command line behind the 'Move' GUI option?

 

[dcsapak]

Dominik, why would the 'Move' GUI option do different things when used at different times?

the difference between online and offline move disk (online -> qemu drive mirror, offline -> qemu-img convert)

What is the command line behind the 'Move' GUI option?

qm move_disk

 

[KirstyA]

Thanks Dominik. I'll do some more tests.