hmm I did not had this issue. Just installed pigz and startet the backup process manually. Load average goes from 7.x%  to 9.x% on an Intel Xeon E3-1245V2
Backup was more than 50% faster.

I would bet you have a too high process priority or IO class of realtime inside your backup template. If you lower that, you should be fine.

Thanks for sharing this. I wonder what will happen on OS updates. Did you ever got trouble with that?

kernel panic not syncing vfs unable to mount root fs on unknown-block"

cpio - premature end of archive

Unable to decompress /boot/initramfs-3-10[....] - unknown format

Error communicating with CLN - Bad request

There might be an even better alternative than lzop, specially when it comes to cpu time. I´am not into academic overoptimization but it seems that´s worth testing under reallife conditions.

Source: https://hannuhartikainen.fi/blog/everyday-compression-tool/

Abstract:
tool    filesize      time  CPU time
pigz      35125348    1.46    8.82
lbzip2  20301117      5.33  32.16
pixz    19333820      34.90  211.77
pzstd  39684543      0.45  2.51

Great results!
@softacoulus: please add the ability to specify the compressor/decompressor that should be used for backups so we do no longer need to do it at OS level.

I've already logged a ticket for this, but if anyone is interested there is a much faster way to do VPS backups by switching out gzip for lzop compression.

Here is a the what the current virtualizor backup does:




When switching the compression method to lzop:



Using gzip : 25.3MB/s and 8min 29 seconds for the backup to complete.
Using lzop : 373MB/s and 38 seconds for the backup to complete.

That is a 1300% increase in backup speed and in reduction in backup time.

Note:
1) During these tests, gzip caused higher server load than lzop (lzop was marginally better).
2) The lzop backup was slightly larger than the gzip (300MB on a 12GB disk), but storage is cheap.
3) The /backup directory is an NFS share from our NAS server, so this also writing is across the network.


We have requested Virtualizor to add this as a backup option, it would greatly help with backing / restoring VM's where hours turn into minutes.

Unfortunately Virtualizor still does not allow to select the compressor binary that it should use, so we need to do it on OS level.

We been using the pzstd and it really works great.

We been using the pzstd and it really works great.

This is such a simple feature for Virtualizor to build in and has the largest quality of life benefit with regard to backups. I simply do not understand why they have not built this in yet.