DragonFly users List (threaded) for 2008-05
Re: 7-Zip / Bzip2
"Samuel J. Greear" <email@example.com> wrote in message
"Matthew Dillon" <firstname.lastname@example.org> wrote in message
:Posted this to kernel@ by accident, please reply here instead :)
:I just wanted to know if there's any interest for the devs to add
:something like p7zip to the base install; even if it's a simple fork
:that only supports 7z. While 7zip is about as obnoxiously slow as
:bzip2, it usually gets much better compression.
:That's not why I'm suggesting it though - what really gets me is that
:bzip2 has no "list" option. Does that 10 gb bzip2 backup archive
:contain 100gb of data, or 200gb? Other than dumping the entire
:archive to /dev/null through wc, there's really no way to do it. Gzip
:will list files, but its compression ratio is awful.
:I imagine that other OSes are going to be watching Dragonfly very
:carefully in the next while as new the features (especially HAMMER)
:mature. Maybe adding 7z will get yet another bandwagon going and
:there will be support across the board :)
Well, I think not in base, at least not unless a lot of people
are using it. p7zip is readily available via the pkgsrc tree
and that's the most reasonable method of accessibility for
I do not know if DragonFly is actively tracking libarchive, but it seems
to be "the ticket" for implementing new archiving/compression methods
through a common mechanism. If one wanted to see 7z functionality
in base implementing a libarchive provider is probably the way to go.
I did a quick test at one point on the dfly distribution ISO and as I
recall 7z was ~60% the size of bzip2 using standard settings.
I got yelled at on IRC for not providing times, so here:
Selected Archiver - Compression Time - Threads - FileSize
dfly-1.12.2_REL.iso - 295,512KB
Bzip2 - 0:27 - 4 - 108,742KB
Bzip2 - 1:24 - 1 - 108,742KB
GZip - 0:55 - 1 - 118,024KB
Zip - 0:55 - 4 - 118,024KB
Zip - 0:55 - 1 - 118,024KB
7Zip - 1:50 - 2 - 73,952KB
7Zip - 3:09 - 1 - 73,952KB
All done via the most unscientific methods available (reporting
user time as displayed by the 7Zip user interface), so treat it
as such. Tested on an Intel Q6600 (4x2.4GHz) w/ single SATA
"Default" compression settings were used across the board.
Everything was tested using the windows 7-Zip program, which
integrates all of these algorithms.