AIX

Originally posted by: OTIT

ERP implementer request to move the paging space to the SAN (DS5020,2 FC disks RAID1). I never configure pgsp of this nature and fear of future problems.

Thank

Originally posted by: Kosala

Primary paging space on the SAN is becoming quite common... specially for VIO setups. For you to do that you have to move the complete rootvg to a SAN volume. Remember that hd6 is a system lv, which is referred by some startup scripts during bootup.

If your concern is having a pgsp on a SAN, why not think of extending the pgsp to a separate paginglv on a SAN LUN without touching hd6.

Kosala

Originally posted by: Renaud

PGSP on san is now implemented in lot of configuration.

If your AIX and your application is correctly tunned, the PGSP is useless ;-).

For your information, one my AIX with rootvg on SAN disk, I get a SAN network failure during several hours AIX lpar works fine and Oracle works fine too.

Originally posted by: SystemAdmin

Not to mention that the SAN disk is probably faster (in any configuration other than the OP suggested). If you DO swap, swapping on a 4+4/R10/300G/15k will be faster than internals.

Originally posted by: OTIT

The paging space for a LUN that preferred path on Controller-A. Extend the LUN to rootvg and only move hd6 to the FC disk.

My question, when DS5020 change the owner preferred path to the Controller-B While high PGSP or the Controller-A damage, AIX which run on the local disk is the problem or not.(I can not move all over the FC disk rootvg because of limited budget)

Originally posted by: Kosala

Definetely it won't crash the OS, but you might get a oatmeal walk feeling... I have tried this on regular circumstances which works fine. But not sure whether the failover will be smooth with a failing SAN controller.

Kosala

Originally posted by: Ashok_AIX_Admin

Basically you need have the rootvg in SAN disk. If hd6 paging size is bigger than 4GB, you may notice high processes waiting for IO resources (VMSTAT "B" column). Especially with ERP software it happens a lot. So my advice would be to spread the paging space across various disks (doesn't have to be same volume group too). Make sure all the paging space are of equal size to get optimal performance.