I think you've entered the realm of difficult problems 8~) (Dealing with extreme cases).

Judging from the little concrete responses, you may be an expert on this than anyone on the list.

Increasing i/o polling count might work. If it doesn't work then here is my reasoning:

From what I gather, increasing that value is like trying to find a balance between processor time and disk i/o time. A process that has a lot of disk i/o leaves the processor idle so the processor might as well work on another process HOWEVER that other process should not be disk i/o intensive but should be processor intensive. HOWEVER (again) a lot of disk i/o processes can be run if there is no bottleneck on disk i/o (thus increasing the throughput of disk i/o processes) and this might be the case if the i/o load is spread over several disks AND THIS IS THE REASON I DON'T THINK increasing the polling count will work for your case i.e. the problem is that your disk i/o is contrained, allowing more disk i/o processes to run doesn't remove the problem.
THEREFORE if most of the processes in your case are disk i/o intensive, increasing the polling count might not work. BUT BY ALL MEANS GIVE IT A TRY and let us know if it works.

8~)
 


--- On Wed, 6/2/10, wambugu esther <essiekui@gmail.com> wrote:

From: wambugu esther <essiekui@gmail.com>
Subject: Re: [Skunkworks] SYBASE ERROR
To: "Skunkworks Mailing List" <skunkworks@lists.my.co.ke>
Date: Wednesday, June 2, 2010, 2:40 PM



On Wed, Jun 2, 2010 at 2:38 PM, wambugu esther <essiekui@gmail.com> wrote:
Thanks,
thought i would contain it by increasing a parameter called i/o polling count and time slice to ensure that alot of i/o processing is not happening often such as applications to take alittle longer in the processor than having alot of i/o being done.
What do u think
Regards
Esther


On Wed, Jun 2, 2010 at 2:16 PM, wesley kirinya <kiriinya2000@yahoo.com> wrote:

Never used it, however:

Increase the I/O throughput or find a way to reduce the I/O and if you can't implement a limit to the allowed I/O, spread the I/O load to other disks. Using disks with faster I/O may also help.

You may not see hardware errors in OS log because it's not a real device failure but a device failure in the context of the DB. Check the generated stack trace. There could be valuable info there.



--- On Wed, 6/2/10, wambugu esther <essiekui@gmail.com> wrote:

From: wambugu esther <essiekui@gmail.com>
Subject: Re: [Skunkworks] SYBASE ERROR
To: "Skunkworks Mailing List" <skunkworks@lists.my.co.ke>
Date: Wednesday, June 2, 2010, 11:27 AM


Dear Rad,
Im getting it if the server is doing alot of I/O last time i got it 5
times,when the server was tring to access a big and busy table..

On Wed, Jun 2, 2010 at 10:27 AM, Rad! <conradakunga@gmail.com> wrote:
> How frequently do you get this error? You may get it when the server
> is doing a lot of IO
>
> On Wed, Jun 2, 2010 at 10:10 AM, wambugu esther <essiekui@gmail.com> wrote:
>> thanks Rad,
>> The product is ASE 12.5.4,Running on HP-UX 11.3 itanium.
>>
>> kind regards
>> Esther
>>
>>
>> On Wed, Jun 2, 2010 at 10:08 AM, Rad! <conradakunga@gmail.com> wrote:
>>> Help people help you
>>>
>>> 1) Which Sybase Product? (ASA? ASE? IQ?)
>>> 2) Which version?
>>> 3) Which OS?
>>>
>>> On Wed, Jun 2, 2010 at 10:04 AM, wambugu esther <essiekui@gmail.com> wrote:
>>>> hey guys..
>>>>
>>>>
>>>> im getting a sybase error  error 694(An attempt was made to
>>>>   read logical page '%ld', virtpage '%ld' from virtual device '%d' for
>>>>   object '%ld' in database '%d'. The page was not read successfully. You
>>>>   may have a device problem or an operating system problem.).
>>>>   The SYBASE write up talks about it being a hardware error but hardware
>>>>   error logs don't show up any problem with the hardware.
>>>>   So was wondering if i increase the rate of I/O polling count which
>>>>   controls the maximum number of processes that Adaptive Server can run
>>>>   before the scheduler checks for disk and/or network I/O completions.
>>>>   has anyone encountered the error and how did they sort it out...
>>>>
>>>> --
>>>>
>>>>
>>>> Best regards
>>>> Esther Wambugu
>>>> _______________________________________________
>>>> Skunkworks mailing list
>>>> Skunkworks@lists.my.co.ke
>>>> http://lists.my.co.ke/cgi-bin/mailman/listinfo/skunkworks
>>>> ------------
>>>> Skunkworks Server donations spreadsheet
>>>> http://spreadsheets.google.com/ccc?key=0AopdHkqSqKL-dHlQVTMxU1VBdU1BSWJxdy1fbjAwOUE&hl=en
>>>> ------------
>>>> Skunkworks Rules
>>>> http://my.co.ke/phpbb/viewtopic.php?f=24&t=94
>>>> ------------
>>>> Other services @ http://my.co.ke
>>>>
>>> _______________________________________________
>>> Skunkworks mailing list
>>> Skunkworks@lists.my.co.ke
>>> http://lists.my.co.ke/cgi-bin/mailman/listinfo/skunkworks
>>> ------------
>>> Skunkworks Server donations spreadsheet
>>> http://spreadsheets.google.com/ccc?key=0AopdHkqSqKL-dHlQVTMxU1VBdU1BSWJxdy1fbjAwOUE&hl=en
>>> ------------
>>> Skunkworks Rules
>>> http://my.co.ke/phpbb/viewtopic.php?f=24&t=94
>>> ------------
>>> Other services @ http://my.co.ke
>>>
>>
>>
>>
>> --
>>
>>
>> Best regards
>> Esther Wambugu
>> _______________________________________________
>> Skunkworks mailing list
>> Skunkworks@lists.my.co.ke
>> http://lists.my.co.ke/cgi-bin/mailman/listinfo/skunkworks
>> ------------
>> Skunkworks Server donations spreadsheet
>> http://spreadsheets.google.com/ccc?key=0AopdHkqSqKL-dHlQVTMxU1VBdU1BSWJxdy1fbjAwOUE&hl=en
>> ------------
>> Skunkworks Rules
>> http://my.co.ke/phpbb/viewtopic.php?f=24&t=94
>> ------------
>> Other services @ http://my.co.ke
>>
> _______________________________________________
> Skunkworks mailing list
> Skunkworks@lists.my.co.ke
> http://lists.my.co.ke/cgi-bin/mailman/listinfo/skunkworks
> ------------
> Skunkworks Server donations spreadsheet
> http://spreadsheets.google.com/ccc?key=0AopdHkqSqKL-dHlQVTMxU1VBdU1BSWJxdy1fbjAwOUE&hl=en
> ------------
> Skunkworks Rules
> http://my.co.ke/phpbb/viewtopic.php?f=24&t=94
> ------------
> Other services @ http://my.co.ke
>



--


Best regards
Esther Wambugu
_______________________________________________
Skunkworks mailing list
Skunkworks@lists.my.co.ke
http://orion.my.co.ke/cgi-bin/mailman/listinfo/skunkworks
------------
Skunkworks Server donations spreadsheet
http://spreadsheets.google.com/ccc?key=0AopdHkqSqKL-dHlQVTMxU1VBdU1BSWJxdy1fbjAwOUE&hl=en
------------
Skunkworks Rules
http://my.co.ke/phpbb/viewtopic.php?f=24&t=94
------------
Other services @ http://my.co.ke


_______________________________________________
Skunkworks mailing list
Skunkworks@lists.my.co.ke
http://lists.my.co.ke/cgi-bin/mailman/listinfo/skunkworks
------------
Skunkworks Server donations spreadsheet
http://spreadsheets.google.com/ccc?key=0AopdHkqSqKL-dHlQVTMxU1VBdU1BSWJxdy1fbjAwOUE&hl=en
------------
Skunkworks Rules
http://my.co.ke/phpbb/viewtopic.php?f=24&t=94
------------
Other services @ http://my.co.ke



--


Best regards
Esther Wambugu




--


Best regards
Esther Wambugu


-----Inline Attachment Follows-----

_______________________________________________
Skunkworks mailing list
Skunkworks@lists.my.co.ke
http://lists.my.co.ke/cgi-bin/mailman/listinfo/skunkworks
------------
Skunkworks Server donations spreadsheet
http://spreadsheets.google.com/ccc?key=0AopdHkqSqKL-dHlQVTMxU1VBdU1BSWJxdy1fbjAwOUE&hl=en
------------
Skunkworks Rules
http://my.co.ke/phpbb/viewtopic.php?f=24&t=94
------------
Other services @ http://my.co.ke