[pve-devel] Speed up PVE Backup

[Dmitry Petuhov]

16.02.2016 13:20, Dietmar Maurer wrote:
>> Storage Backend is ceph using 2x 10Gbit/s and i'm able to read from it
>> with 500-1500MB/s. See below for an example.
> The backup process reads 64KB blocks, and it seems this slows down ceph.
> This is a known behavior, but I found no solution to speed it up.
Just done script to speedup my backups from ceph. It's simply does 
(actually little more):
rbd snap create $SNAP
rbd export $SNAP $DUMPDIR/$POOL-$VOLUME-$DATE.raw
rbd snap rm $SNAP
for every image in selected pools.

When exporting to file, it's faster than my temporary HDD can write 
(about 120MB/s). But exporting to STDOUT ('-' instead of filename, with 
compression or without it) noticeably decreases speed to qemu's levels 
(20-30MB/s). That's little strange.

This method is incompatible with PVE's backup-restore tools, but good 
enough for manual disaster recovery from CLI.