ProLiant DL380 G3 I/O Bottleneck

[Andrew_235]

Hi,

Hoping someone can help. I have a ProLiant DL380 G3 with 1GB RAM and 3 x 18.2GB SCSI Ultra320 15k drives in a RAID 1 configuration.

We are experiencing massive i/o bottleneck problems. Using performance monitor our average % Disk Time is 80+ percent (over a 12-24 hour period).

The system is running SQL server 2000. It is also set as a Domain Controller, however the domain is very small with only a handful of users and a max of 15 connections at any one time.

Any ideas/suggestions?

Andrew

[Prashant (I am Back)]

Hi,

Is the read operation is more or write operation on HDD. We can set these paramtre under ACU.

Regards,

[Andrew_235]

Hi,

It appears as if we are doing more writing than reading.

[SAKET_5]

Hi Andrew,

as prashant indicates if you believe there is more write operations than read on the server, you can set a higher write cache ratio than read on the array accelerator. So here is how you do that:
from windows, fire up ACU (generally found under HP system tools -> Array Configuration Utility. Select the SA5i controller in embedded slot, then on the right hand side click on the "Controller Settings" and under "Cache ratio" specify appropriate read/write cache ratio.

If you do not have ACU installed on the server, download it from the link below:
http://h18023.www1.hp.com/support/files/server/us/download/14185.html

hope this helps and don't forget to assign points:)

regards,

[SAKET_5]

Hi Andrew,

how do you monitor the disk time counter, are you just using perfmon on windows or a system management software?

You could also run HP PAT (performance assessment utility) and test the disk read/write/sequential read/etc on the various drives/volumes on the system.

do you have the latest system BIOS and the latest firmware on the drives?

Have you enabled disk caching from within Windows on OS level disks that Windows sees?

hope it helps and don't forget to assign points:)

regards,

[Andrew_235]

Hi Saket,

When running the ACU, i get no other option than 100% read, 0% write. Is this normal? How do i change this?

I have the latest BIOS and firmware updates.

Will check on the OS side of caching and let you know.

Regards,
Andrew

[SAKET_5]

Hi Andrew,

that would be the case if your SA5i did not come with BBWC (battery backed write cache).

Note, without BBWC, write caching is too dangerous and hence you could only set 100% read. Are you sure you are not using Proliant DL380 G2?

P.S.Could you please assign points to the replies.

Thanks,

[Andrew_235]

No doubt, i have a DL380 G3.

What other options do I have? Is there anything else I can do to improve our i/o performance?

Andrew

[Andrew_235]

Hi again,

Would I be better off to use RAID 1+0? Can this be done 'on the fly' while the system is online?

What performance will I see over RAID 1 using this method?

How do I configure RAID 1+0 under ACU?

Thanks for your help,
Andrew

[SAKET_5]

Hi Andrew,

So, why do you have three disks in a RAID 1 set? Is this your system partition and data both?

I very much doubt that you will gain much by going from RAID 1 to RAID 1+0. I am also not sure if this RAID migration is supported on SA5i.I will check it for ya.

hope it helps and dont forget to assign points:)

regards,