No space left while moving disk

[mira]

@mira thank you for your suggestion.
Please let me know if I understand it correctly.

You suggest to resize both volumes (x 1.7 and x 2.4) and then move the volumes from ZFS to ext4?

You say, newly created raw disk on ext4, which should have the exact size as the previous zvol (530 GB), is not big enough for uncompressed data from ZVOL, correct?

This would imply, that inside LXC, users also see the compressed data usage instead of actual data usage, correct?

I guess PM should at least implement a warning when moving LXCs from compressed FS to noncompressed FS in PM GUI.
However, even better it would be, to have GUI calculate and propose new size and resize it before moving data.
I guess I could open a bug report of feature request.

The FS overhead could be more on ext4 as well, so just resizing the disk based on compression might not be enough.

There are many different ways to handle this situation, and even uncompressed to uncompressed might lead to an 'out of space' error because of different overhead. So that's something you have to keep in mind whenever changing the storage of a CT. It would probably be best to mention it in the docs.