Virtual shared memory: aio pool

Hi! IDS 9.40FC6 onstat -g mem | grep aio Pool Summary: name class addr totalsize freesize #allocfrag #freefrag aio V 21e0c6040 670588928 105694536 816895 179934 onstat -g seg Segment Summary: id key addr size ovhd class blkused blkfree 3501 1381386241 10a000000 4278190080 549248 R* 1044480 0 3002 1381386242 209000000 4278190080 131216 V 1044254 226 3003 1381386243 308000000 4257218560 130576 V 824336 215024 2504 1381386244 405c00000 3145728 752 M 583 185 Total: - - 12816744448 - - 2913653 215435 AIO pool is a ~ 8% of virtual shared memory Who use aio pool? What is placed in the aio pool? How can i decrease aio pool?

"Who use the aio pool" Any users writing to chunks that are not using kaio. And the server read/writing filesystem files e.g. writing to message log, reading onconfig file on startup, reading message files if an error occurs. "What is place in the aio pool" I assume AIO (non-KAIO) disk I/O requests by AIO VPS "How can I decrease the aio pool" You cannot. That is how the server does the disk i/O above. So what if it is 8% of virtual memory?

AIO not used. aio statistics over 90 minute # onstat -g iovIBM Informix Dynamic Server Version 9.40.FC6 AIO I/O vps: class/vp s io/s totalops dskread dskwrite dskcopy wakeups io/wup errors kio 0 s 352.2 2184024 2083609 100415 0 3765988 0.6 0 kio 1 s 330.7 2050476 1955007 95469 0 3457337 0.6 0 kio 2 s 331.7 2056702 1965950 90752 0 3517246 0.6 0 kio 3 s 342.3 2122757 2026712 96045 0 3637924 0.6 0 kio 4 s 332.7 2062812 1971107 91705 0 3519426 0.6 0 kio 5 i 319.9 1983505 1897005 86500 0 3375505 0.6 0 kio 6 i 316.1 1960053 1874118 85935 0 3329851 0.6 0 kio 7 s 294.2 1824125 1744131 79994 0 3089365 0.6 0 msc 0 i 8.3 51166 0 0 0 49066 1.0 0 aio 0 i 0.1 521 0 519 0 521 1.0 0 aio 1 i 0.0 0 0 0 0 0 0.0 0 aio 2 i 0.0 0 0 0 0 0 0.0 0 aio 3 i 0.0 0 0 0 0 0 0.0 0 aio 4 i 0.0 0 0 0 0 0 0.0 0 aio 5 i 0.0 0 0 0 0 0 0.0 0 pio 0 i 0.0 0 0 0 0 0 0.0 0 lio 0 i 0.0 0 0 0 0 0 0.0 0 At night, when user activity is a small - size of the aio pool(sysmaster:syspoollst.po_usedamt+sysmaster:syspoollst.po_freeamt) is a 571MB + 107 MB = 678 MB Virtual SHM - 8 GB at 10:00, size of the aio pool - 580 + 108 = 688 MB

AIO is used for things that are not raw devices and hence do not support KAIO.. - writting to the online.log is avways done via AIO - reading the onconfig file is always done via AIO - reading/writing connectivity files under /INFORMIXTMP - reading/writing $INFORMIXDIR/etc/.infos and .conf files Perhaps it is also used for something else... Maybe temporary sort files that under $DBTEMP?? raise a support call with IBM..i am just guessing here.