Option to choose backup compression type

[bmarkus]

Backup is using gzip compression. Made some test on my live TC with different compressions:

7.4M - standard mydata.tgz using gzip
7.0M - mydata.bz2 using bzip2
5.4M - mydata.xz using XZ

As you can see XZ gives significantly smaller backup than others. XZ in general offers the best compression in most cases. Now it is spreading. There are sites offering download in .xz format, latest GNU tar now supports it, etc.

I would appreciate if compression method would be configurable and XZ would be an option.

For more info on XZ see http://tukaani.org/xz/

[curaga]

It also takes considerably more time to compress and decompress than gzip.


Bzip2 could be an option, but I don't see XZ as one, since the utility is not in the base (not in busybox either, AFAIK).

[bmarkus]

Bzip2 do not give too much benefits therefore out of the game. My idea is to have an option to use xz or anything else when it is installed by the user and not to add it to the base. Saved data is restored after extensions are loaded, so decompression can't be a problem.

Regarding speed, user can decide preferences over spped or size. Also you can tune xz parameters I guess.

[roberts]

Lets revisit after 2.4 goes final.

[bmarkus]

Thanks...