Hey guys,
Thanks for the support,
The Increase of the following parameter worked ,Time slice ,i/o polling count and i/o batch  size.

The i/o batch size helps in ensuring that the I/O subsystem is not flooded with many simultaneous writes,therefore reducing i/o contention.
then Time slice parameter  helps to reduce the task switching between one processor to another..helps in ensuring a task is held alittle longer before switching it and fetching another.
i/o polling count:increases the number of processes that can be run before a fetch from disk or network has been done.
This all reduced the contention of doing lots of fetches from disks..but the disadvantage of this is you have to compromise on response time alittle..
But this is a bug in SYBASE which has been fixed in ASE 15.0.

But the above solution can server you for the time being.
Thanks

On Thu, Jun 3, 2010 at 10:36 AM, wesley kirinya <kiriinya2000@yahoo.com> wrote:

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://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




--


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




--


Best regards
Esther Wambugu