finding my kvm harddisk in ZFS

[Madhatter]

Hi, my apologies upfront if this is a very stupid question but I don't get it and it's freaking me out, not understanding it.
Can anyone please educate me.

For the record Proxmox 5.0-5/c155b5bc BETA but I doubt that has anything to do with my question.

I used the full ZFS install so I ended up with a single rpool.
Messing with a win10 KVM so for performance reason I created a rpool/asyncio (uncompressed asynchronous IO / who cares about the data its windows
In the VM creation, i selected qcow2.
So the KVM has VM-500-disk1 and works fine, however, in my little world, I was expecting a qcow2 file presenting the disk under /rpool/asyncio but it wasn't.

in zfs list I do find
rpool/asyncio 40.8G 502G 100K /rpool/asyncio
rpool/asyncio/vm-500-disk-1 40.8G 502G 40.8G -

I was desperate enough to run a find over the whole host but there is no qcow2 file. Nothing

I did find
/run/udev/links/\x2fzvol\x2frpool\x2fasyncio\x2fvm-500-disk-1-part2
/run/udev/links/\x2frpool\x2fasyncio\x2fvm-500-disk-1-part2
/run/udev/links/\x2fzvol\x2frpool\x2fasyncio\x2fvm-500-disk-1-part1
/run/udev/links/\x2frpool\x2fasyncio\x2fvm-500-disk-1-part1
/run/udev/links/\x2fzvol\x2frpool\x2fasyncio\x2fvm-500-disk-1
/run/udev/links/\x2frpool\x2fasyncio\x2fvm-500-disk-1
/dev/zvol/rpool/asyncio/vm-500-disk-1-part2
/dev/zvol/rpool/asyncio/vm-500-disk-1-part1
/dev/zvol/rpool/asyncio/vm-500-disk-1
/dev/rpool/asyncio/vm-500-disk-1-part2
/dev/rpool/asyncio/vm-500-disk-1-part1
/dev/rpool/asyncio/vm-500-disk-1

But that wasn't really what I was expecting to find.

The reason why I was looking for the file was to check its current size after some updates and whether I should shrink it, as its backup was 41GB for a 23GB install.

I Ubuntu KVM I compressed the qcow2 files after sdelete the free space and I wanted to look if I have to do the same in Proxmox.

Can anyone please educate me where my thinking goes off in this?
is rpool/asyncio/vm-500-disk-1 basically my file and therefore A) I can't shrink it b) I can't see / access it?

Has anyone perfested tweaked zfs vs ext4 for a qcow2 disk and would I be better to create an ext4 partition for KVM files?

Thanks for some insight hints.
Andreas

 

[fireon]

Hello Madhatter,

you must change your mind in ZFS:
https://pve.proxmox.com/wiki/Storage:_ZFS
https://pve.proxmox.com/wiki/ZFS:_Tips_and_Tricks
https://pve.proxmox.com/wiki/ZFS_on_Linux

Never create an VM on top of ZFS directly with qcow2 ore something similar!!! This what you have done is the ext4 or lvm-way. ZFS is designt to work with datasets. Datasets are very powerfull and easy to handle.

You write:
> In the VM creation, i selected qcow2.
but zfs list show some disk...

never turn off compression, the system is much more slower. Please post also "zpool status"


You must have an storage (not a directory) that called zfs as format. There is an default storage added at the and of the ZFS PVE installation. Sorry but i don't know the name exactly, but when you have a look at the storagetab, you should see.

You also can add an other ZFSdataset (for KVM/LXC) in the storagetab.

It makes no sense to write here everything about the differences between ZFS-Datasets and qcow2. Please read a little in this links what i've postet. If you have any question about, ask!