[Samba] idmap_rid/idmap_hash collisions?

Nick t31 at 2thebatcave.com
Tue Nov 10 19:34:13 MST 2009

Is it possible for the uid/gid numbers that are generated by the
idmap_rid and idmap_hash to collide if there are a large number of
users or groups?  I cannot seem to find any documentation on the
limitations of these plugins.  Before using I want to make absolutely
sure that there won't be any collisions.

In doing some research about Likewise Open, I see it's hashing routine
can have this problem:

"If your Active Directory relative identifiers, or RIDs, are a number
greater than 524,287, the Likewise Open algorithm that generates UIDs
and GIDs can result in UID-GID collisions among users and groups. In
such cases, it is recommended that you use Likewise Enterprise or that
you use the Likewise UID-GID management tool."


I was somehow thinking that Likewise is based on Samba, although I
don't remember where I heard that so it could be total BS.

Does anyone know about the limitations of these idmap backends?

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