On Thu, 25 Aug 2011 09:45:38 -0400 gene heskett <[email protected]> wrote:
> That could be handy if it is easily configured to be used, which I > have not investigated. http://wiki.zmanda.com/index.php/How_To:Use_pigz_to_speed_up_compression > Making amanda use its parallelism might be a > challenging project however. Other emails on this list indicate that using pigz does speed up amanda runs. Just for the halibut, I did a bit of testing on an otherwise idle desktop with two AMD cores. I created a tarball using my /var directory. Then: root@dzur:/# time pigz var.test.tar real 6m1.411s user 9m5.290s sys 0m44.550s root@dzur:/# ll var.test.tar.gz -rw-r--r-- 1 root root 6786436232 2011-08-25 10:07 var.test.tar.gz root@dzur:/# time gzip -d var.test.tar.gz real 4m16.611s user 1m43.080s sys 0m38.410s root@dzur:/# ll var.test.tar -rw-r--r-- 1 root root 9458923520 2011-08-25 10:07 var.test.tar root@dzur:/# tar -tf var.test.tar # output omitted; no error messages root@dzur:/# time gzip var.test.tar real 9m45.992s user 8m23.070s sys 0m32.970s root@dzur:/# ll var.test.tar.gz -rw-r--r-- 1 root root 6785153296 2011-08-25 10:07 var.test.tar.gz root@dzur:/# gunzip var.test.tar.gz root@dzur:/# ll var.test.tar -rw-r--r-- 1 root root 9458923520 2011-08-25 10:07 var.test.tar root@dzur:/# pigz --version pigz 2.1.6 root@dzur:/# Note that gzip took noticeably longer but produced a marginally smaller output file (possibly due to different default compression values; I did not investigate). Testing the output file as above produced no error message. The uncompressed tarball retained its size. I used gzip -d to test rather than pigz -d in order to verify compatibility. While we're at it, I am glad I never did implement bzip2 compression for Amanada: root@dzur:/# time bzip2 var.test.tar real 157m54.710s user 156m41.360s sys 0m35.550s root@dzur:/# ll var.test.tar.bz2 -rw-r--r-- 1 root root 6780647698 2011-08-25 10:07 var.test.tar.bz2 root@dzur:/# -- Charles Curley /"\ ASCII Ribbon Campaign Looking for fine software \ / Respect for open standards and/or writing? X No HTML/RTF in email http://www.charlescurley.com / \ No M$ Word docs in email Key fingerprint = CE5C 6645 A45A 64E4 94C0 809C FFF6 4C48 4ECD DFDB
