Re: [Bug-tar] GNU tar 1.20

[Antonio Diaz Diaz]

Kevin Day wrote:
> For the record, LZIP has a different binary header.
> Instead of LZMA's "\xFFLZMA", it seems to only have: "LZIP"

There are two different file formats sharing the .lzma extension. The 
header of one format begins with "\xFFLZMA\x00". The other format lacks 
magic bytes in the header. It also lacks error checking.


> Here are it's times relative to bzip2, gzip, and lzop (lzip has a
> scary 9minute compression time):

I expect future versions of lzip to be a little faster, but it will 
always be slower than bzip2. As stated in lzip's home page:
"Lzip is not a replacement for gzip or bzip2, but a complement; which 
one is best to use depends on user's needs. Gzip is the fastest and most 
widely used. Bzip2 compresses better than gzip but is slower, both 
compressing and decompressing. Lzip decompresses almost as fast as gzip 
and compresses better than bzip2, but requires more memory and time 
during compression".


> -rw-r----- 1 turtle turtle  75M Sep 10 02:38 linux-2.6.26.3-olpc.tar.lz
> -rw-r----- 1 turtle turtle 198M Sep 10 02:38 linux-2.6.26.3-olpc.tar.lzo
> -rw-r----- 1 turtle turtle 142M Sep 10 02:38 linux-2.6.26.3-olpc.tar.gz
> -rw-r----- 1 turtle turtle 111M Sep 10 02:38 linux-2.6.26.3-olpc.tar.bz2

Given that a tarball is "compressed by one, decompressed by many", I 
think lzip is the clear winner here, even being the slowest at compression.


Regards,
Antonio.