Thick provisioned disks, VMFS volume runs out of disk space.....

[Hextet]

Hey guys,

so I'm running Debian on ESXi. I created 2, 800GB Thick Provisioned Lazy Zeroed disks and installed the OS, which leaves me with 27GB free on the two drives I used.

I install the OS, everything is fine and dandy, however when running the OS eventually I'll get an error and the OS will crash saying there is no space left on the VMFS volume, I browsed the datastore and on each VMFS volume there was a file that consumed the rest of the available disk space, which makes NO sense since I used two thick provisioned disks. The file names are something like "openmediavault_1-000000001.vmdk"

I'm really confused as to why this is happening since I'm using thick provisioned disks, it should NOT be happening.

[larsonm]

Sounds like the VM has a snapshot.

Also note that, without a memory reservation, a vswp file equal to the size of RAM allocated to the VM.

[Hextet]

I deleted all snapshots, Also I only allocated 5GB of RAM.

So if I don't have snapshots this should never happen?

edit:

Even after deleting snapshots it still wouldn't boot, including the "xxx-000001.vmdk" files. swap pace wouldn't be an issue as there was 27GB left on both datastores. I'm spinning up a new VM now and will not use snapshots, and see what happens.

[larsonm]

Is the VM named "openmediavault"? 

It's possible that, if there was a snapshot, that snapshot is still in the process of committing once deleted.

Is there some sort of backup software that takes a snapshot while backing up the VMDK?

If the VM RAM is set at 5GB and Thick provisioned disk is configured for 800GB, and no snapshots are in place, it is very unlikely that there would be more than 805.5GB of disk used (the vm log files and vmx vswp which covers the RAM allocated as overhead to run the machine).

[Hextet]

Yea the VM is named "openmediavault?

I see, maybe I'll avoid snapshots then. No there is absolutely no backup system of any sort for the VMDK. I have data backup through openmediavault when it's running so I haven't lost any data, just extreme annoyance with having to respin my VM.

edit:

If I take a snapshot of a thick provisioned disk, I would need equal free space of the size of the VMDK right?

[a_p_]

Once you create a snapshot, a new delta virtual disk (<vmname>-00000x.vmdk) is created and used to store all subsequent changes. This way each delta/snapshot .vmdk file can grow up to the provisioned size of the base virtual disk (plus some MB for metadata), independent of thin or thick provisioned virtual disks.

André