Re: OpenLDAP, bdb and Linux filesystems

["Jong" <jongchoi@OpenLDAP.org>]

> With the BDB cache living in mmap'd files by default, increasing the BDB
> cache size may not help very much. This may be an argument for using shared

In recent Linux, there is little difference bw. regular file access and file memory
mapping when it comes to caching. mmaped pages are also maintained in the
page cache and they can remain dirty in the main memory unless they have to
be replaced or synced.

> memory instead, in these cases. You can try this in OpenLDAP 2.2, see the
> "shm_key" config keyword for back-bdb.

Yes. this may be an argument in addition to the fast restart we talked of before.
BTW, I have a problem in setting up this today (though I did once) :
Setting shm_key <#> in slapd.conf generates the following message:
slapadd: could not add entry dn="..." (line #): txn_begin failed: Invalid argument(22)
any idea ?

- Jong