Re: HP-UX

Hi

If most of your operations are tiny I/O operations such as index scans then your SAN statistics would not show anything that could alert you and your SAN Administrator. I had a similar problem last year with a EMC DMX San, when I went to ask the SAN Admini he was showing me how good was SAN's buffer hit ratio and how much bandwidth the SAN still has (was only 50% busy according to him).

Not sure if you have enabled the read cache in your HDS SAN?

If you are using Online JFS you would use the tipical parameters such as convosync = direct, mincache = direct, nodatainlog, delaylog

On 8/14/06, Alfonso León <aleon68_at_gmail.com> wrote:
>
> Hi Every one:
> we went online today with full load, until last week we were 20% loaded,
> and CPU Utilization with less 10%. We have a HPUX with 10 cpus and a
> Hitachi SAN. Oracle 9.2.0.6. CPU utilization is now 40%.
>
> Today the performance was way more less than expected.
>
> these are the top wait event
>
>
> Top 5 Timed Events
>
> ~~~~~~~~~~~~~~~~~~ % Total
>
> Event Waits Time (s) Ela Time
>
> -------------------------------------------- ------------ -----------
> --------
>
> db file sequential read 1,768,294 38,259
> 39.69
>
> log file sync 71,190 30,065
> 31.19
>
> free buffer waits 12,212 11,351
> 11.78
>
> buffer busy waits 360,596 8,773
> 9.10
>
> CPU time 2,736
> 2.84
>
> db file scattered read 382,133 1,691
> 1.75
>
> db file parallel read 2,958 1,199
> 1.24
>
> log file parallel write 5,193 1,073
> 1.11
>
> enqueue 1,649 698
> .72
>
> SQL*Net message from dblink 54,991 141
> .15
>
> As you can see i'm waiting on disk, the path utilization of the san is
> less than 20% and the CPU utilization is less than 40%. almost all the
> processes are sleeping.
>
> On the HP-UX monitor says that peak disk utilization is 100% the rest of
> the parameters are normal and sub-used.
>
> Does anybody know if there is parameter in kernel that limit the disk
> request?
>
> Any idea would be appreciated.
>
>
> Alfonso Leon
>

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