Options for using pigz for faster backups in command_backup.sh

[drphlux]

Hello.
Pigz compresses using threads to make use of multiple processors and cores.
I've made my own local changes utilizing pigz for backups instead of gzip in this script.

examples:
tar --use-compress-program=pigz
tar cf - paths-to-archive | pigz -9 -p 32 > archive.tar.gz

This could possibly benefit more users, speeding up the backup process. It helps a lot for me.
Maybe even enable options for describing how many cores to use?

What do you think?

PS: there are some more examples here:
https://stackoverflow.com/questions/36917882/how-to-use-pigz-with-tar

[drphlux]

Here some examples from my server:
Regular backup using gzip:

vhserver@valheim:~$ ./vhserver backup
[  OK  ] Backing up vhserver: Backup starting
* Previous backup was created less than 1 day ago, total size 813M
[  OK  ] Backing up vhserver: Completed: vhserver-2021-03-04-114952.tar.gz, total size 813M
* Total compression time: 44.19 seconds with 105% CPU usage

Using pigz:

vhserver@valheim:~$ ./vhserver backup
[  OK  ] Backing up vhserver: Backup starting
* Previous backup was created less than 1 day ago, total size 813M
[  OK  ] Backing up vhserver: Completed: vhserver-2021-03-04-115622.tar.gz, total size 812M
* Total compression time: 8.86 seconds with 793% CPU usage

Bonus - using zstd (zstdmt):

vhserver@valheim:~$ ./vhserver backup
[  OK  ] Backing up vhserver: Backup starting
* Previous backup was created less than 1 day ago, total size 798M
[  OK  ] Backing up vhserver: Completed: vhserver-2021-03-04-124623.tar.zst, total size 798M
* Total compression time: 2.08 seconds with 406% CPU usage

The actual code:

compression_time=`/usr/bin/time -f "* Total compression time: %e seconds with %P CPU usage" \
                tar -I zstdmt -cf "${backupdir}/${backupname}.tar.zst" \
                -C "${rootdir}" --exclude "${excludedir}" --exclude "${lockdir}/backup.lock" ./. \
                2>&1 > /dev/null`

[pmgledhill102]

To close the loop on this. Looks like it was implemented: #4509