Marten Lehmann wrote:

Hello,

does openldap implement sort of caching?

Yes.

Or does it completely rely on the underlying database like bdb (default)?

No.

Read the documentation.

I'm noticing an intensive i/o load while the complete slapcat export of our ldap data is only about 34MB big so everything besides writing/updating should fit into the memory.

Caching only helps if a particular piece of data will be used more than once. When you slapcat a database you extract every entry once and never use it again. I.e., most cache settings have very little benefit for slapcat.