topic Re: MSA2000 RAID 10 limit (max 16 HDDs)? in HPE EVA Storage

MSA2000 RAID 10 limit (max 16 HDDs)?

Martin11 — Tue, 21 Jul 2009 22:28:48 GMT

Hi,
our company bought HP StorageWorks 2212fc (with Dual Enhanced Controller) + second MSA2000 Drive Enclosure.
During the instalation/configuration we were able to setup the RAID 10 array consist of max 16 HHDs.
Using of MSA2000 family arrays for high-performance appliance is due to this big (and very strange) limitation practical impossible.

Is there a way how to setup a RAID 10 array with more that 16 HDDs with our MSA2000?

Otherwise I can't understand for what purpose is good to have MSA2000 with 3 another drive enclosure (48xHDD in total). If is not possible to setup one big and fast array.
Or why is not writen this radical limitation in specification of MSA2000 (with big bold letters)...

Re: MSA2000 RAID 10 limit (max 16 HDDs)?

Niels Vejrup Pedersen — Wed, 22 Jul 2009 07:58:39 GMT

Hello,

Max for a RAID 10 VDISK is 16.

You can go to 32 disks when using RAID 50.

What configuration are you looking to use it for ?

Regards

Re: MSA2000 RAID 10 limit (max 16 HDDs)?

Martin11 — Wed, 22 Jul 2009 08:35:03 GMT

Hi,
we want to have high-performance & safe array for virtualization. This array will be used also for file server, witch is used by our coders - for working/compiling with many thousands of source files.
And for these purposes is the best one RAID 10 consist of many HDDs (I think).

But why have MSA2000 this limitation? And why it isn't written in spec/docu-mentation?
Maybe just for marketing reasons? Without this limitation MSA can be powerful almost like significantly more expansive EVA.

Re: MSA2000 RAID 10 limit (max 16 HDDs)?

Niels Vejrup Pedersen — Wed, 22 Jul 2009 10:49:07 GMT

I can't tell why the limitations are in place, but it's written in the user guide to the msa2000.

A 16 disk RAID 10 can be fast enough to many workloads, you can just create more than one of them if you need additional performance...

Regards

Re: MSA2000 RAID 10 limit (max 16 HDDs)?

Martin11 — Wed, 22 Jul 2009 11:14:50 GMT

O.k. Thank you for your responses and endeavour.

Performance with speed about 320 MBps may be enough for many people, just as may not be.
Especially if they paid 40 000 Å for this "fast array"...

Re: MSA2000 RAID 10 limit (max 16 HDDs)?

Patrick Terlisten — Thu, 23 Jul 2009 05:36:44 GMT

Hello,

think about the maximum vdisks size of 16 TB. With 1 TB SATA disks this would be achieved with 16 disks. A RAID 5+0 is build by striping two RAID 5 arrays, so each RAID 5 can be up to 16 TB, with 32 TB in sum for the RAID 5+0.

Don't use large arrays with giant volumes for virtualization. For example VMware recommends datastore sizes between 500 and 750 GB with 15 hosts and up to 25 guests.

Best regards,
Patrick

Re: MSA2000 RAID 10 limit (max 16 HDDs)?

Martin11 — Thu, 23 Jul 2009 12:22:53 GMT

Hello,

just a little correction: With 16x1TB disks in RAID 10 would be achieved only 8 TB vdisks size...

And here is what I found in documentations:

QuickSpecs - NOTHING:
http://h20195.www2.hp.com/v2/GetPDF.aspx/c01404634.pdf

Product Manuals (User Guide) - NOTHING:
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c01394283/c01394283.pdf

Reference Guide - BINGO:
http://bizsupport2.austin.hp.com/bc/docs/support/SupportManual/c01534303/c01534303.pdf
"Table 3-1 Number of Disk Drives Supported for Each RAID Level"

So this RAID 10 limitation is "by design". And customers who need higher perfomance have to looking for EVA, or another manufacturer.