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Re: Write changed immediately to disk

Chris G. Sellers wrote: 
Is this more of an OS issue versus an OpenLDAP issue?  Since OpenLDAP
does not have raw access to the physical disk, it depends on the OS to
flush it's buffers, so hitting reset on a system like that may cause
things to get lost in the cache/buffer for the file system??

Possibly. The original poster didn't mention what version of OpenLDAP or what backend he's using. No guarantees with back-ldbm. With back-bdb and default settings, the transaction log is written synchronously and flushed after each write. With OpenLDAP 2.3 and newer, the auto-recovery on startup will replay the transaction log, so anything that didn't make it back into the database files originally will be recovered. Of course, synchronous writes of the transaction log still may get lost if the hard drive caches the writes but reports that they completed successfully. 

Sellers

On Feb 18, 2008, at 2:37 AM, ml@bortal.de <mailto:ml@bortal.de> wrote:

Hi,

Howard Chu schrieb:
ml@bortal.de <mailto:ml@bortal.de> wrote: 
Hello List,

what settings do i need to write my ldap changes (almost) immedialtely
to disk?
I do not need much of performance but would rather have a higher
security.


That is the default behavior for slapd, no other settings are needed.

In my case i add a samba user to my ldap DB, then after 15 seconds i
reset that box by pressing the reset button.
After the box has rebootet the added user is not there anymore.

So i am not quite sure if its really writing to disk streight away.

Thanks, Mario 

______________________________________________
Chris G. Sellers | NITLE - Technology Team
734.661.2318 | chris.sellers@nitle.org <mailto:chris.sellers@nitle.org>
AIM: imthewherd | GoogleTalk: cgseller@gmail.com <mailto:cgseller@gmail.com>



--
  -- Howard Chu
  Chief Architect, Symas Corp.  http://www.symas.com
  Director, Highland Sun        http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP     http://www.openldap.org/project/