zfs on linux virtual machine within freenas

[paulk]

I'm considering creating an Ubuntu 18.04 virtual machine with a zfs root file system on my freenas 11.3 system (see https://wiki.ubuntu.com/ZFS and https://github.com/openzfs/zfs/wiki/Ubuntu). I want to make sure that this is not a terrible idea. I'm hoping that I will be able to schedule periodic zfs snapshot tasks and cloud sync backups of the VM's file system from freenas.

Has anyone tried anything like this before?

Any gotchas to avoid?

Thanks!

 

[Yorick]

Whytho? If it's a virtual disk, ZFS doesn't give you any advantage over ext4, does it?

 

[paulk]

Whytho? If it's a virtual disk, ZFS doesn't give you any advantage over ext4, does it?

I would like to schedule periodic zfs snapshot tasks and cloud sync backups of the VM's file system from the FreeNAS host. This would only be possible if the zfs file system on the virtual disk is accessible to the FreeNAS host itself. Do you know if it would be?

 

[Patrick M. Hausen]

No, it would not. It's only accessable from within the VM as long as the VM is running. You can pull some tricks to get at the pool from FreeNAS but the VM must be shut down for that.

 

[paulk]

No, it would not. It's only accessable from within the VM as long as the VM is running. You can pull some tricks to get at the pool from FreeNAS but the VM must be shut down for that.

OK. Thanks for the explanation.

 

[Patrick M. Hausen]

You can snapshot and replicate the ZVOL holding your virtual disk just fine. And if you absolutely must get at the data from a non-linux system as a worst-case recovery procedure, you can.

See https://www.freebsd.org/doc/handbook/filesystems-linux.html