Re: Transparent compression for Btrfs

Eric Anopolsky
2008-09-01T02:49:57Z

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On Mon, 2008-09-01 at 07:39 +0530, Balaji Rao wrote:
> Hi,
>
> For a medium term project, I'm thinking of working on transparent compression
> for Btrfs. Please give any hints and comments on how we would want to go
> about this, the features we would like to have and some common pitfalls to
> avoid.
>
> Is looking at how it's done in Reiser4, a good idea ? Can we allow the
> compression algorithm be configurable on a per file basis, may be using an
> xattr ? This, for example, would allow us to make a compromise between speed
> and compression ratio.
>
> Any other ideas welcome.

If the algorithm is tunable on a per file basis, why not make the
compression level tunable on a per file basis? I think it's also
important to consider the tradeoff the between learning
curve/administrative overhead and the granularity of control over
compression, but I don't have any good answers.

While we're on the subject, someone on the ZFS list expressed a need to
tune redundancy on a per-file basis (or even tune redundancy at all
after the filesystem is created). Currently ZFS is very inflexible in
this regard, so it could be a way for btrfs to get ahead.

Cheers,
Eric

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