id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	launchpad_bug
1354	compression (e.g. to efficiently store sparse files)	zooko		"I was just re-reading [http://doc.cat-v.org/plan_9/4th_edition/papers/fossil/ the Fossil/Venti tech docs] and realized that their method of omitting trailing zeroes from each block might be adapted to Tahoe-LAFS to efficiently store sparse files. (Tahoe-LAFS would do this per Tahoe-LAFS ""segment"" where Venti did it per Venti ""block"".)

This is of course a very specific form of compression and might be subsumed by more general compression instead.

On the other hand compression -- either the specific ""remove runs of zeroes"" compression from Venti or more general compression -- is often a lose at this layer since the biggest files are almost always uncompressable (because they are already compressed).

Are sparse files common?"	enhancement	new	major	undecided	code-encoding	1.8.2		compression space-efficiency performance