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IBM has evaluated the priority of this enhancement proposal relative to other future product content and determined that this RFE will not be pursued for a future product release.
As a follow-up on the discussion around this item:
If you have truly cold virtual memory that you are not using, then putting it in paging space can be a very good thing, to free up RAM for your main workload. Its very possible that the pages evicted are related to startup of Oracle and seldom or never used later.
If the complaint is that you are concerned that when or if you may need those pages, you will incur a hiccup due to page-in activity, then the solution is simple: add more memory. If your goal is not to page at all ever, even at startup of Oracle, then you simply do not have enough memory in your LPAR.
If you run paging space garbage collection or swap-off the primary paging space to correct the problem, then when you recycle Oracle it will re-occur and you will have to repeat the process.
Customers who do not want to page should configure their LPARs proportionally to their max workload.
There will always be some non-zero amount of paging space reserved for AIX Kernel Memory Manager Metadata, called XPTs. These are structures created proportional to the virtual memory footprint of an LPAR's workload. In an environment where there really is no page-out activity, there can and will still be some amount of paging space reserved in case AIX needs to page-out an XPT (at some point in the future). So paging space utilization will never be completely zero due to this reservation mechanism for this one case. For very large virtual workloads, this reservation can get quite large. Since there were paging space disk blocks charged to an Oracle process in this case, it does not look like XPTs are the issue here, but, instead legitimate paging for a period probably during Oracle startup.
please see comments
AIX development is requesting information describing why the suggestions made in the RFE do not satisfy whatever the problem is (which seems to be that on AIX they see a constant 2% usage of paging space).
There are two suggestions in the RFE:
1. Swap-on/off
2. Background garbage collection (psgc)
Can you explain why these do not apply or will not work for the problem?
vmo settings of rpgclean and scrubclean can be used to have the OS perform garbage collection on swap pages when they have been re-read, and when they have never been written.
You can one-off clear such pages with swapoff and swapon. If you have only one paging space, make a temporary one first, or use chps to decrease and then increase it.
Exceptions to the above garbage collection options:
If a page is written to swap (not just allocated), but is never read after that, then it will stay in swap until it is freed by the application. This might be from an application design issue where it should be a memory mapped file instead of reading data that never gets used.
If early paging space allocation is set, then every page in RAM will be allocated on disk. This can be enabled in vmo, or with an environment variable, and is the default in older versions of AIX.