Hi Frank,

by rsync to hdd, do you mean copying the db files or slapcat the
output to a file?
The first one seems to be a db killer if the db is in use while copying it. :)
I think the only safe way is by doing a slapcat after every write to
the db (accesslog?).

Anyway, sounds like a nice idea to me to get a big performance boost.
Have you considered SSDs instead of ramdisks?
Imo its the more safe and nearly as fast as ramdisk alternative. :)

Bye, Benjamin.

On Tue, Oct 19, 2010 at 10:40, Frank Bonnet <f.bonnet@esiee.fr> wrote:

Hello

I'm thinking to put db files in RAM instead of hard disk
for performance reasons.

FreeBSD ( and Linux thought ) provide some utility to build
RAMDISK ( md )

I did some tests in rebuilding db files with the slapcat/slapadd
commands

with RAMDISK

ldap3# time slapadd -l test.ldif
/usr/local/etc/openldap/slapd.conf: line 110: rootdn is always granted
unlimited privileges.
#################### 100.00% eta   none elapsed             20s spd 633.9
k/s

WITH HARDDISK

ldap3# time slapadd -l test.ldif
/usr/local/etc/openldap/slapd.conf: line 110: rootdn is always granted
unlimited privileges.
#################### 100.00% eta   none elapsed          04m22s spd  48.4
k/s

Does anyone runs production servers with ramdisk ?

I know it is risky but running rsyncd between ramdisk and a hardisk depot
would be safe huh ?

Thanks for any advices