RE: OpenLDAP, bdb and Linux filesystems

["Pierangelo Masarati" <ando@sys-net.it>]

>
>> The background of the question is that we encountered performance
>> problems with subversion (which also stores the data in a berkeley-db)
>> when the database was stored on an ext3-FS. On closer examination we
>> found out, that for a simple testcase (Import of a 40MB repository)
>> ext3 was about four times slower than ext2 (and reiserfs wasn't too
>> much better than ext3, while xfs wasn't too much slower than ext2). It
>> seems to me, that berkeley-db and ext3 (and reiser) filesystems don't
>> play together too well.

ext3 and reiser are journaling filesystems, while ext2 is not.
So, when using db4 on ext3/reiser, double journaling is taking
place: the fs one, and the db4 one.  On ext2, only db2 journaling
is taking place.  I expect that some caching advantages can be
achieved when writing 40 Mb of data if an appropriate cache is
given to both the journaling procedures.

Ando.

-- 
Pierangelo Masarati
mailto:pierangelo.masarati@sys-net.it