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Re: Restore Takes long time

 
Mahmoud_1
Frequent Advisor

Restore Takes long time

Dear All,
I have two SDLT Tapes attached to two Alpha Servers ES45 clustered on HSG80, Running OpenVMS 7.3-2 and Oracle RAC 9.2.0.5 .
Problem is when a failure occurred we need more than 20 hours to restore 100gb.
Note the disks formatted as ODS-5.
I tried to restore the data on another system with disks formated as ODS-2 it takes only 3 hours.
Oracle is not my responsibility in this site.

Any OpenVMS suggestions will be appreciated.
Regards
16 REPLIES 16
Marc Van den Broeck
Trusted Contributor

Re: Restore Takes long time

Mahmoud,

I have done some testing with ods-2 and ods-5 and found no difference in speed while copying files.
But, I found differnces between a mirror set and a raid-5. Copying to the raid-5 took 2 times longer.
So, can you check whether you are using mirrored discs are raid?
But even then a factor of almost 7 has to have another cause. Or you using the same tape device?

Rgds
Marc
Mahmoud_1
Frequent Advisor

Re: Restore Takes long time

OK Van,
I have Data on raid-5 and raid-1.
I have same case on singl Systems (DS25,ES40,ES45) with no raid.
Regards.
Wim Van den Wyngaert
Honored Contributor

Re: Restore Takes long time

Are there FDDI shadow disks (or other slow connections ? What tape drive did you use in both tests ? What process quotas for the users that did the test ?

Wim
Wim
Volker Halle
Honored Contributor

Re: Restore Takes long time

Mahmoud,

in general, performance problems are hard to discuss and speculate about in a forum like this.

As you can see from the questions raised already, you need to provide a lot of data and details about your performance problem, if you expect more than just more questions and speculation.

You need to describe:

- the command(s) used
- the HW config involved (down to the disk/tape layer)

Volker.
Jan van den Ende
Honored Contributor

Re: Restore Takes long time

Mahmood,

Do the ODS-5 disks have High-watermarking enabled?
It _IS_ the default, and so easily overlooked.
That WOULD explain slowdown of this magnitude.

If yes, do you REALLY need it?
$ SET DEVICE xxx/NOHIGH will help here.

Worth checking...

Proost.

Have one on me.

jpe
Don't rust yours pelled jacker to fine doll missed aches.
Mahmoud_1
Frequent Advisor

Re: Restore Takes long time

Dear All,
In fact I dont have shadow disks or volumes.
About the backup command its simple:
$backup/log/image/ignore=(inter,nobackup) $1$dga30: mkb500:disk3.bck
and the restore its the same.

Regards.
Wim Van den Wyngaert
Honored Contributor

Re: Restore Takes long time

As Volker said, we are missing a lot of data.
Also on controller level there are settings that can influence performance.

Wim
Wim
Mahmoud_1
Frequent Advisor

Re: Restore Takes long time

Thanks all for fast response,
I will returne to the site HW Engineer for more information about the HW configuration.
Regards.
Mahmoud_1
Frequent Advisor

Re: Restore Takes long time

Hi to All,
H/W enginer sent me the Tape specifications:
KZPBA-CA SE SCSI Controller
HP SDLT 160/320GB Tape Drive

Best Regards.