[Dovecot] DoveCot compression to save HDD space

[Dan Price]

On Thu 15 Feb 2007 at 08:55AM, Host Expert wrote:
> Hi,
> 
> Ok, thanks for comments.

Note also that Apple is including ZFS in the next generation of MacOS,
so Solaris will not be your only choice.

> How effective is ZFS ? I mean yeah, even Windows has file system 
> compression... And what ? Is very poor...

You've not said how much performance you are willing to trade for
space savings.

The compression currently in ZFS is a variant of Lempel-Ziv with some
tweaks.  This has the advantage of being fast and compresses moderately
well; for the curious, see
http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/uts/common/os/compress.c
In my personal experience, it is lightweight enough that it's hard
to know it is present without benchmarking.  And as I said before, it
has the curious property of *accelerating* some workloads.

Adam Leventhal has done most of the work to include GZIP compression in
ZFS, and we expect to see him check that in sometime "soon"; see
http://blogs.sun.com/ahl/.  The issue with GZIP is that it's not as
fast.  The good news is that you will be able to choose-- and since
everything is an online operation, it's not too hard to switch things
back and forth.

I fear that we are running the risk of hijacking this mailing list
to talk about ZFS :)  You may want to check out
zfs-discuss at opensolaris.org and/or google for "zfs".

        -dp

-- 
Daniel Price - Solaris Kernel Engineering - dp at eng.sun.com - blogs.sun.com/dp