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Can autoRAID running RAID 5 go back to 0/1 on a Progress Database

Francisco Lopez_2
Occasional Contributor

Can autoRAID running RAID 5 go back to 0/1 on a Progress Database

Few weeks ago, we experience a tremendous grow on our progress database system
making my autoraid moved to RAID 5. after that my progress database application performance is down on the ground. If I add more hard drives to my autoraid box will that take me back to RAID 0/1 automatically?
IT is the field to be
10 REPLIES
Brian M. Fisher
Honored Contributor

Re: Can autoRAID running RAID 5 go back to 0/1 on a Progress Database

I believe that by adding drives to an AutoRAID that has shifted data into RAID 5, the data will only go into RAID 0/1 as it is written back to disk. Not really automatically.

The following URL Understanding AutoRAID Write Working Set Metric might help you out.

http://www.hp.com/essd/model12H_writews.html

Brian
<*(((>< er
Perception IS Reality
CHRIS ANORUO
Honored Contributor

Re: Can autoRAID running RAID 5 go back to 0/1 on a Progress Database

No, it will not. Raid 5 is better than 0/1. Check your scsi connections
When We Seek To Discover The Best In Others, We Somehow Bring Out The Best In Ourselves.
Brian M. Fisher
Honored Contributor

Re: Can autoRAID running RAID 5 go back to 0/1 on a Progress Database

To respond to Chris:
RAID 0/1 and RAID 5 provide redundancy to guard against data loss. RAID 0/1 offers superior write performance, while RAID 5 has a significant cost advantage.

Check out the HP AutoRAID web pages:
http://www.enterprisestorage.hp.com/products/disk_array/autoraid/index.html

Brian
<*(((>< er
Perception IS Reality

Re: Can autoRAID running RAID 5 go back to 0/1 on a Progress Database

As per the the URL passed to you by the first responder, you would need to add further disk to the AutoRaid unit. The paper discusses ways to regain the Write Working Set space needed for Raid 0/1 to allow you to regain some performance boost from his configuration.
Unfortunately, as you have seen, RAID 5 is very good for data protection, but what you gain on the swing, you loose on the roundabout, namely performance.
My house is the bank's, my money the wife's, But my opinions belong to me, not HP!
Venu_2
Regular Advisor

Re: Can autoRAID running RAID 5 go back to 0/1 on a Progress Database

Hi,

Definetly RAID 0/1 gives you better performance than RAID 5.

For autoraid to keep the DATA in RAID 0/1 you should leave more unallocated space. You can upgrade the disk, add to the LUN and leave it unallocated.


Hope this helps

venu

Shyam Kishore
Frequent Advisor

Re: Can autoRAID running RAID 5 go back to 0/1 on a Progress Database

Hi,

AutoRaid is clever enough to decide what data to put in RAID 5 or RAID 1/0. Most frequently used data will be kept in RAID 1/0 and the remaining in RAID 5. As the RAID 1/0 takes more space you should have enough free data area in AutoRAID Box .

IF the capacity of the data and the capacity of autoRAID Box is very close, you may get bottleneck in performance. To over come you may add some additional Disks to the AutoRaid.

All the best

-Shyam

Kids learn from masters, masters from mistakes.
Emmanuel Eyer
Frequent Advisor

Re: Can autoRAID running RAID 5 go back to 0/1 on a Progress Database

Just to emphasize a bit more: add drives. It will definitely increase your performance. A couple of seconds (or minutes, depends on the load) after adding the drives the AutoRAID will show "balancing" and lights will blink like a Christmas Tree. Balancing is basically using the extra disk space for more RAID 0/1, thus extra performance. It is perfectly true that an AutoRAID with most of it in RAID 5 is not very much performant - even HP admits it.

Have fun, Emmanuel
CHRIS ANORUO
Honored Contributor

Re: Can autoRAID running RAID 5 go back to 0/1 on a Progress Database

Thank you so much Brian, I have just read this: http://www.enterprisestorage.hp.com/pdfs/idc_autoraid.pdf

My reseller hasn't been forthcoming on this storage issues.

may be I will open up a trade-off for you!

When We Seek To Discover The Best In Others, We Somehow Bring Out The Best In Ourselves.
CHRIS ANORUO
Honored Contributor

Re: Can autoRAID running RAID 5 go back to 0/1 on a Progress Database

Definetly RAID 0/1 gives you better performance than RAID5, but automatic migration of data from RAID 0/1 to RAID 5 storage-Substantially reduces administrative overhead.

When We Seek To Discover The Best In Others, We Somehow Bring Out The Best In Ourselves.
Philip Chan_1
Respected Contributor

Re: Can autoRAID running RAID 5 go back to 0/1 on a Progress Database

My colleague has done some in-house performance testing against Raid 0/1 and Raid 5. I was told that Raid 0/1 out perform Raid 5 by significantly margin.