topic P2000 G3 FC, Raid Level Question in MSA Storage

P2000 G3 FC, Raid Level Question

Patrick Neuner — Tue, 29 Nov 2011 13:00:07 GMT

Hello,

using the P2000 G3 FC (dual controller) with 1 disk enclosure and 8 HDDs for Web-Hosting (httpd / mail / mysql / ...)

Lately we got some performance issues and thinking about repartioning.

Now I wanted to ask what you guys think will give us the best possible performance. (cost/GB and final capacity is not interesting - just performance; also ignore missing global spare in my ideas ... we buy if we do the new layout)

P2000 is connected to Blade Center - 3 Blades (with virtual machines on them) connect to the P2000. Other Blades connect to EVA4100.

Here my thoughts what could give best performance:
-----

8HDD in RAID 10 (downside - this single VDISK is only presented over 1 controller - so the second one is idling around ...)
4HDD in RAID 10 over controller A; 4HDD in RAID 10 over controller B
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8HDD in RAID 5 (downsite - single VDISK - only 1 controller)

4HDD in RAID 5 presented over controller A; 4HDD in RAID 5 presented over controller B
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    2HDD in RAID 1 presented to controller A - attached to Blade 1
    + 2HDD in RAID 1 presented over controller A attached to Blade 2
    + 2HDD in RAID 1 presented over controller B attached to Blade 3
-----

I hope you can help me on this! ;-)

Thank you, bye from Austria

Andreas

Re: P2000 G3 FC, Raid Level Question

Torsten. — Tue, 29 Nov 2011 13:10:27 GMT

The 2x 4 HDD in RAID10 sounds not bad. By doing so, each controller can own a vdisk. I would create as many sub-vdisks as possible.

Re: P2000 G3 FC, Raid Level Question

Johan Guldmyr — Tue, 29 Nov 2011 20:23:10 GMT

What kind of disks do you have?

If you want to give equal performance to each server then 8HDD in RAID10 sounds better to me than 2x4 RAID10. Because you have three servers.

Also I don't think 4HDD are going to hit the roof of one controller, I doubt 8HDD are either, but I have no numbers to back that. Is 100MB/s ok per disk in optimal conditions for a SATA drive? What for a SAS 15k?

If you don't want equal performance (supposedly the sql one wants more) then the 2x4HDD RAID1 makes sense.

parity raid is a no-no when you're talking performance (especially for write intensive applications)

Re: P2000 G3 FC, Raid Level Question

Patrick Neuner — Thu, 01 Dec 2011 09:19:11 GMT

using 7,2k SATA disks - so the controller speed should no problem.

The possible IOPS should be about the same with 2 RAID10 4HDDs and 1 RAID 10 8HDDs, or?

Andreas

Re: P2000 G3 FC, Raid Level Question

Johan Guldmyr — Thu, 01 Dec 2011 09:51:33 GMT

Yes.

// Johan