Doesn't that depend on the use case. My knowledge about using OpenLDAP is mostly in 99% read and just 1% write operations, while a SSD is very good in 99% of the operations and only 1% writes, which is also cached in RAM.
It's bad if a SSDs takes its time for 1% writing as long as 99% reading, thats smells like a little bit of benchmarking. :) Bye. On Tue, Oct 19, 2010 at 11:32, Howard Chu <[email protected]> wrote: > Frank Bonnet wrote: >> >> Hello >> >> Yes maybe safier to use slapcat ... >> >> I haven't any SSDs for now so I tested ramdisk >> did you perform tests with SSD ? > > A good SSD can work, but it will cost quite a bit and RAM is still an order > of magnitude faster. Also, most of the SSDs available now are still poor for > random writes, which is the main performance bottleneck. (All of my PCs are > on SSDs now; they're great for fast boot times but without a big RAM cache > they're still dog slow.) >> >> thanks >> >> On 10/19/2010 11:00 AM, Benjamin Griese wrote: >>> >>> 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<[email protected]> 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 >>>> >>>> >>> >>> >> > > > -- > -- Howard Chu > CTO, Symas Corp. http://www.symas.com > Director, Highland Sun http://highlandsun.com/hyc/ > Chief Architect, OpenLDAP http://www.openldap.org/project/ > -- To be or not to be -- Shakespeare | To do is to be -- Nietzsche | To be is to do -- Sartre | Do be do be do -- Sinatra
