Re: Transparent compression in the FS

[Erik Bourget <erik@midmaine.com>]

Erik Mouw <erik@harddisk-recovery.com> writes:

> On Wed, Oct 15, 2003 at 05:50:38PM +0400, Nikita Danilov wrote:
>> Erik Mouw writes:
>>  > Nowadays disks are so incredibly cheap, that transparent compression
>>  > support is not realy worth it anymore (IMHO).
>> 
>> But disk bandwidth is so incredibly expensive that compression becoming
>> more and more useful: on compressed file system bandwidth of user-data
>> transfers can be larger than raw disk bandwidth. It is the same
>> situation as with allocation of disk space for files: disks are cheap,
>> but storing several files in the same block becomes more advantageous
>> over time.
>
> You have a point, but remember that modern IDE drives can do about
> 50MB/s from medium. I don't think you'll find a CPU that is able to
> handle transparent decompression on the fly at 50MB/s, even not with a
> simple compression scheme as used in NTFS (see the NTFS docs on
> SourceForge for details).
>
> Erik
>
> PS: let me guess: among other things, reiser4 comes with transparent
>     compression? ;-)

Reiser4 made my coffee this morning, it's wonderful :)

Seriously, though, (and getting off the topic), has anyone started to use
reiser4 in a high-load environment?  I've got a mail system that shoots a few
million messages through it every day and a filesystem that's faster with
creating and deleting tons of ~4kb qmail queue files (with data journaling!)
would be verrry innnteresting.

- Erik Bourget