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Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

 
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abrsvc
Respected Contributor

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

To verify that the adapter is the culprit here, I would confirm by using the same test on a system with an adapter that has the cache enabled.  If the adapter is the problem, then the new test should show a significant performance difference.  Also, as stated by Hoff, process quotas etc can significantly affect Backup performance.  For the confirmation testing, be sure that the accounts, quotas etc be consistant.

 

Dan

robert70
Valued Contributor

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

ran the test on another disk connected via another adapter - restore as quick as backup - adapter write cache looks like the problem
robert70
Valued Contributor

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

how can the write cache on the P411 be set? is this software enabled?
Volker Halle
Honored Contributor

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

robert70,

 

Battery:
Battery is not reported as present.

 

That could be a reason. Storage controllers typically don't allow you to use WRITE caches, if there is no battery available !

 

Volker.

robert70
Valued Contributor

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

understood - so either i have a hardware problem in that controller or more likely the controller dosent have the battery installed and hence no write cache enabled
Hoff
Honored Contributor

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

Or the battery has failed; cache batteries have been known to do that.

 

Call hardware services.  

 

Your organization pays good money for that access into HP, use it.

abrsvc
Respected Contributor

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

Per the documentation the HP 650 battery is required to enable the write cache feature. With the battery "not present", the write cache is thus disabled.

Check the battery cable connection. I have seen these get dislodged. Even a re-seat might help.

These batteries run about $60 or so.

Dan
robert70
Valued Contributor

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

thank you very much for your help
i have now riased this with HP who are organising a battery and 512mb cache kit
cheers to all