Paul, When tuning "maxperm", one important thing should be noted: "maxperm" is not the limit on cached file pages! Under heavy JFS file I/O, the file cache can grow up to "maxperm" by paging out process data areas (I think AIX documentation refers to them as "computational" pages) - if there is free memory beyond maxperm, the file cache will continue to grow and consume all available free memory. In other words, maxperm defines the limit where the file cache will *compete* with processes for memory.
So if you have a system with a known "small" application load and no real need for VM paging, I don't see a reason why not to set maxperm very low, to let the file cache only consume real "free" memory. As an example, here's one of our boxes: number of valid memory pages = 2097141 maxperm=8.0% of real memory maximum pinable=80.0% of real memory minperm=3.0% of real memory number of file memory pages = 847688 numperm=40.4% of real memory Of course, I'm pretty sure if you use raw logical volumes, all of this goes out the window. Our TSM server is a Sun (with raw logical volumes), so I can't tell exactly how AIX will behave. Cheers, Paul Ripke UNIX/OpenVMS Sysadmin CSC, Port Kembla 2502, NSW, Australia Phone +61 2 4275 4101 Fax +61 2 4275 7801 Mobile +61 419 432 517 101 reasons why you can't find your Sysadmin: 68. It's 9 AM. He/she is not working that late. ---------------------------------------------------------------------------------------- This email, including any attachments, is intended only for use by the addressee(s) and may contain confidential and/or personal information and may also be the subject of legal privilege. Any personal information contained in this email is not to be used or disclosed for any purpose other than the purpose for which you have received it. If you are not the intended recipient, you must not disclose or use the information contained in it. In this case, please let me know by return email, delete the message permanently from your system and destroy any copies. ----------------------------------------------------------------------------------------
