Backups are still slow.
The suggestion is to have –compress-filter=pigz` set as default.
pigz will see that there are only a few cores or threads in an old laptop and adjust to it.
But the machines running qubes usually have a lot of cores, except if they are older laptops. So a desk heater, also known as a workstation should have enough cores to make a significant difference. Also during backup most or all VMs are down, so there is lots of cores and lots of RAM sitting around unemployed.
I see NO compatibility issue as pigz is just a parallel gzip. So why not saving us a lot of time by having this option set as default.
Cheers
luja