ioo help

[normntwrk]

Last week I ran ioo -p -o numfsbufs=512 on a server and it rebooted over the weekend. I expected it to change all the values to 512 but it only changed the reboot value. Any ideas what I can do differently? I am still seeing increasing values for:
712897 filesystem I/Os blocked with no fsbuf



Box is on 5.2.05

# ioo -L|grep fsbuf
numfsbufs 186 186 512 1 2G-1

Thanks

Norm

 

[khalidaaa]

What does it show in the /etc/tunable/lastboot.log?

Try:

ioo -o numfsbufs=512

Regards,
Khalid

 

[normntwrk]

Rather odd...

Running in pre 5.2 tuning mode - values in nextboot file ignored


The nextboot log has this
ioo:
numfsbufs = "512"
~

 

[normntwrk]

Well that seemed to change one more parameter, not sure what it will look like on next boot (a week away)

# ioo -L|grep fsbufs
numfsbufs 512 186 512 1 2G-1


Thanks

 

[p5wizard]

IMHO, if you're running in pre52 tuning mode, you have to provide your own scripting to set ioo, vmo parameters...


HTH,

p5wizard

 

[normntwrk]

thanks, I'll look into that

Norm

 

[khalidaaa]

Compatibility Mode
When running in pre 5.2 compatibility mode (controlled by the pre520tune attribute of sys0, see Introduction to AIX 5L Version 5.2 tunable parameter setting in the Performance Management Guide), reboot values for parameters, except those of type Bosboot, are not really meaningful because in this mode they are not applied at boot time.

In pre 5.2 compatibility mode, setting reboot values to tuning parameters continues to be achieved by imbedding calls to tuning commands in scripts called during the boot sequence. Parameters of type Reboot can therefore be set without the -r flag, so that existing scripts continue to work.

This mode is automatically turned ON when a machine is MIGRATED to AIX 5L Version 5.2. For complete installations, it is turned OFF and the reboot values for parameters are set by applying the content of the /etc/tunables/nextboot file during the reboot sequence. Only in that mode are the -r and -p flags fully functional. See "AIX 5L Version 5.2 kernel tuning" in the Performance Tools Guide and Reference for details about the new AIX 5.2 mode.

http://www.cepba.upc.es/docs/ibm_doc/manaix/cmds/aixcmds3/ioo.htm

Regards,
Khalid

 

[khalidaaa]

This link will help much better:

http://www.ibm.com/developerworks/aix/library/au-Keung_AIXPerf.html

Regards,
Khalid

 

[normntwrk]

Does anyone have a sure fire example of how to do this? This server is 3000 miles away and the only examples I've seen call it from the inittab which I really hate to play around with as we know the box won't boot if it gets corrupted

Thanks again

Norm

 

[p5wizard]

So, why don't you turn off pre52 compat mode and use the nextboot files as per the standard smit screens or ioo -p name=value / vmo -p name=value commands?


HTH,

p5wizard

 

[normntwrk]

How does one turn off the pre52 compat mode?

 

[p5wizard]

smitty chgsys

               Change / Show Characteristics of Operating System

Type or select values in entry fields.
Press Enter AFTER making all desired changes.

[MORE...2]                                              [Entry Fields]
  Maximum number of PROCESSES allowed per user       [500]                   +#
  Maximum number of pages in block I/O BUFFER CACHE  [20]                    +#
  Maximum Kbytes of real memory allowed for MBUFS    [0]                     +#
  Automatically REBOOT system after a crash           true                   +
  Continuously maintain DISK I/O history              false                  +
  HIGH water mark for pending write I/Os per file    [0]                     +#
  LOW water mark for pending write I/Os per file     [0]                     +#
  Amount of usable physical memory in Kbytes          23068672
  State of system keylock at boot time                normal
  Enable full CORE dump                               false                  +
  Use pre-430 style CORE dump                         false                  +
  [red]Pre-520 tuning compatibility mode                   disable                +[/red]
  Maximum login name length at boot time             [9]                     +#
[MORE...11]

F1=Help             F2=Refresh          F3=Cancel           F4=List
F5=Reset            F6=Command          F7=Edit             F8=Image
F9=Shell            F10=Exit            Enter=Do

use TAB key to toggle between enable and disable



HTH,

p5wizard

 

[normntwrk]

Thanks, I looked for that and couldn't find it anywhere

I'm going to try that on a box we have here that was upgraded to 5.2 after I do a mksysb

Norm