overview zlib efficiency?

Robert L Mathews
Tue, 15 Mar 2016 18:41:29 -0000

On 3/15/16 10:13 AM, Sven Hartge wrote:

> I don't have a script, but I can provide some numbers. I did a test
with
> a server for about 10.000 users and 2TB worth of mail, converting from
> Maildir++ to mdbox with zlib (level = 6) and had a final size of 1TB, so
> 2:1 reduction.

These numbers roughly match my results. About 6 TB of mail compresses
down to about 3 TB.

The difference in ongoing CPU use for compression "on the fly" of
newly
arriving mail, and decompression of mail from the disk, is unnoticeable
on my servers.

Also keep in mind that even if it does increase CPU usage, it reduces
disk usage. This is probably an excellent tradeoff for most people,
since most servers are limited by disk throughput/latency more than CPU
power.

--
Robert L Mathews, Tiger Technologies, http://www.tigertech.net/