Re: virt-sparsify ?
On Mon, 2022-12-12 at 04:53 -0800, ToddAndMargo via users wrote:
On 11/9/22 08:28, ToddAndMargo wrote:
> Any downside to ths tool?
>
> https://libguestfs.org/virt-sparsify.1.html
Yes, BIG, BIG downside!
dump/restore can not restore the fiel correctly.
dump restores a qcows drive as a blank drive
Restor (not dump) will restore sparse files as expanded files, i.e.
with the uncopied sections filled in with nulls. That is entirely
normal (cp and most other utilities will do the same thing unless told
otherwise). The resulting file should look exactly the same as the
original, except for occupying more physical space.
However virt-sparsify presumably also messes with the guest filesystem
metadata (inode, FAT, whatever) when doing this, so that the guest
system still sees a functioning filesystem. If so, I wouldn't expect
dump/restor to recognise that, so maybe that's where the problem lies.
poc