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 iov
IBM 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:sys poollst.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.

After restart IDS size increase to 1MB

after 2 day work - total size 168MB
free 26MB

All connection ipcstr