[Bug-tar] Performance difference between 1.15.1 and 1.20

[Jaco van der Schyff]

I upgraded tar on two linux servers that I use for backup and restore.

My dataset is 2.2 TB and I noticed the following (significant)
difference

tar-1.15-1:

Backup:  36.373 hours @ 16.5 MB/hour
Restore: 57.067 hours @ 10.5 MB/hour

tar-1.20:

Backup:   37.88 hours @ 16.0 MB/hour
Restore: 142.98 hours @  4.2 MB/hour


The backup times are close enough, my problem is with the restore
time; an increase of 250%.  The only thing changed on my system
was the version of tar.

If this is not a know issue, or a unique occurence in my case, I could
run 1.20 for backup and 1.15.1 for restore, but I don't really want to
have two differnt versions installed.

Am I missing something?


- Jaco van der Schyff