choosing a file system

[Pascal Gienger]

Henrique de Moraes Holschuh <hmh at debian.org> wrote:

> Ext4, I never tried.  Nor reiser3.  I may have to, we will build a brand
> new Cyrus spool (small, just 5K users) next month, and the XFS unlink
> [lack of] performance worries me.

Nobody likes deletes. Even databases used to mark deleted space only as 
"deleted" until a vacuum (Postgres) or other periodical maintenance command 
was run. Cyrus offers a similiar construct named "delayed expunge". Before 
we migrated our mail system to Solaris 10 it ran on Linux 2.4 with XFS on a 
FC SAN device. Deletes were extremely slow so we had to delay the expunges 
until the weekend, even on night they were too slow and too IO congesting.

On the other hand, XFS was the only Linux filesystems capable to handle our 
5 million files (at that time, we're now at 33 million) we had in these 
days with an acceptable performance. Ext3 was way too slow with directories 
with > 1000 files (but many things have changed from kernel 2.4.x to 
nowadays kernels), IBM jfs was not stable (it crashed during a high load 
test, which was an immediate k.o.). We were reluctant to use Reiser then as 
it was "too new" in 2001.