Extended file cache size

[Jeff Wolfe_1]

When doing a sho mem, I'm seeing that 50% of memory is allocated to file cache. (see attached) With only 150K out of 2M pages available on the free list, how do I get some of this memory back? Is VMS manageing this pool of memory? Are there SYSGEN parameters fo manage the pool?

Thanks in advance...

Jeff

[Craig A Berry · Accepted solution]

See section 18.5 of the System Manager's manual on controlling the size of the XFC cache. The dynamic system parameter VCC$MAX_CACHE sets the maximum size, but you should really read that section of the manual before deciding if that's what you reall want to do.

[Martin P.J. Zinser]

Hello Jeff,

there should be no need to limit the size as XFC is supposed to give up on memory if it is needed by other processes.

Greetings, Martin

[Willem Grooters]

Jeff
In addition to Martin:

VMS manageing this pool of memory?

definitely YES. So don't worry.
(Am I right that this is just paged memory which will be freed when required? Then 'file cache' is to be considered an ordinary 'user', so it would mean that with a lot of users, the cache will shrink.)

Are there SYSGEN parameters fo manage the pool?

Follow Craig's suggestion. It will tell you how to with what. But I would suggest to let VMS take care unless you know exactly what you do. You may ruin the cache's performance otherwise.

Willem

[Jeff Wolfe_1]

Thanks for the responses!

Jeff