Originally posted by: SystemAdmin

Hi all,

I have a p570 with 16 processors (32 logical), 64 GB RAM, 16 internal SCSI disk and 380 DS6800 luns.
Running AIX 5300-05-04 and DB2 v8.1.

My question is: is the following AIO configuration reasonable?

root:/>lsattr -El aio0
autoconfig available STATE to be configured at system restart True
fastpath enable State of fast path True
kprocprio 39 Server PRIORITY True
maxreqs 32768 Maximum number of REQUESTS True
maxservers 10 MAXIMUM number of servers per cpu True
minservers 160 MINIMUM number of servers True

root:/>pstat -a |grep aio|grep -v posix|wc -l
320

My dubt is: the maxservers=10 statement implies 320 AIO servers in the practice? (because 10 * 32 logical processors = 320)

Thanks in advance.

Regards,
Andres.

#AIX-Forum

Originally posted by: MarkTaylor

Yes it is 10 * Logical CPUs. Now, whether your system needs 10 per CPU is another matter. Keep an eye on how many are started after a week or so of the system running and this will let you know how many you should start. If all 320 are started, then you could look at increasing this value, but be warned there is a memory overhead for each one started and if you start too many you will have to reboot to kill them off etc..

Rgds
Mark Taylor
#AIX-Forum

Originally posted by: bhead

Not sure if that's a typo but I'm seeing your minimum number set at 160, I think the default is 1 for minimum. Since your max is 10 per cpu I don't think it'll make any difference, just looks a little odd.

If you aren't already using Nigel's NMON tool (IBM freeware monitor tool) you could download it and watch how many AIO's are actually being used. Better yet set it up to take samples over time. If it tops out you know you don't have enough.

> Hi all,
>
> I have a p570 with 16 processors (32 logical), 64 GB
> RAM, 16 internal SCSI disk and 380 DS6800 luns.
> Running AIX 5300-05-04 and DB2 v8.1.
>
> My question is: is the following AIO configuration
> reasonable?
>
> root:/>lsattr -El aio0
> autoconfig available STATE to be configured at system
> restart True
> fastpath enable State of fast path
> True
> kprocprio 39 Server PRIORITY
> True
> maxreqs 32768 Maximum number of REQUESTS
> True
> maxservers 10 MAXIMUM number of servers per
> cpu True
> minservers 160 MINIMUM number of servers
> True
>
> root:/>pstat -a |grep aio|grep -v posix|wc -l
> 320
>
> My dubt is: the maxservers=10 statement implies 320
> AIO servers in the practice? (because 10 * 32 logical
> processors = 320)
>
> Thanks in advance.
>
> Regards,
> Andres.
>

#AIX-Forum