Re: [Gnu-arch-users] Storage efficiency of revlibs

[Mikhael Goikhman]

On 06 Dec 2005 13:34:40 +0100, Ludovic Courtès wrote:
> 
> IOW, the use of hard links yields a compression ratio of 4 (!).

One of my partially populated revlibs shows ratio of 2.6 (342Mb / 130Mb).
This ratio highly depends on many factors. Still, it is very low,
comparable with or lower than gzip.

I.e. we both may just cacherev every revision to get the same disk usage
without needing to keep so many inodes for old revisions. And if you only
make one cacherev per 25 revisions, you get 25 times less of disk usage.

In reality, my source-only trees (containing normal {arch}, no pristines)
produce tarball that is 10% of the "du -s tree". So for my projects, the
tarball ratio is 10, and the revlib ratio is 2.5. Then the "cacherev
every 50 revisions" solution is 200 times more compact than revlib.

Regards,
Mikhael.