[Borgbackup] Reducing backup times for raw VM images, with zfs send?

[Bzzzz]

On Wed, 18 May 2022 10:05:52 -0700
Mason Schmitt via Borgbackup <borgbackup at python.org> wrote:

> Today I primarily use Borg to backup sparse KVM raw disk image files
> and soon I plan to use Borg to backup VM disks stored directly on ZFS
> zvols (in a Proxmox environment).
>
> My experience with backing up KVM sparse disk image files is that
> even if there have been very few changes to the VMs (mostly just
> writes to files in /var/log) backups still take several hours to a
> locally attached USB 3 disk.

I doubt it is USB3 fault, as a SSD on a Rpi4 read speed is an average of
235 MB/s.

Did you change the --chunker-params or did you left it genuine ?

Jean-Yves