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Oracle and MLOCK

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Oracle and MLOCK

Hello, Forum

I am trying to migrate 300 GB Database Instances from the V-class machine to the N4000. Both are running 11.0 OS.
2 databases coexist well on the V server. In order for me to bring them up on the N machine, I have to put
entry in /etc/privgroup :
dba MLOCK , otherwise the second instance dosn't start and gives an HP-UX error: not owner. I have checked /dev/async driver to be owned by dba. My max_async_ports is the same on both machines. Can anyone explain why I need to MLOCK Oracle and what kernel parameters I need to change to avoid setprivgrp command.
Is this a clean way of doing it?

Thanks a lot.
Roger Baptiste
Honored Contributor

Re: Oracle and MLOCK


MLOCK is a privilige which can be assigned to a group. The users of the group who have this privilige can "lock" process text and data in to memory and also lock shared memory segments. THis is very much needed to run oracle instances; Hence in any box where oracle is run, we include this privilige.

To see the current priviliges on the system , run
It will show the set priviliges.

(What was the setting in your V box?? )

I don''t think there is any kernel parameters to override this.

For more info do
man 1m setprivgrp

Take it easy.
Ryan Kogelheide
Frequent Advisor

Re: Oracle and MLOCK

I've seen this too. I have two identically configured clusters and the first needs MLOCK and the second seems to run fine without it. I haven't checked to see if /dev/async is opened on the second (i don't have privs), but it is definitely open on the first.

The Metalink <133007.1> talks about it
Note 139272.1 also talks about async config.