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msa-20 preformance problem

arie_5
Contributor

msa-20 preformance problem

i think you will find this helpful
We have 4 msa-20 systems. Each connected dl360G4 using ms6402 controller. We have notice that the new MSA-20 are performing slow relative (5MBps) to the new one (65MBps) for writing on raid-5. After a system check we found the battery on the MSA-20 is not charge and the accelerator is disabled.
7 REPLIES
Andrew_168
Regular Advisor

Re: msa-20 preformance problem

Thank you Arie,

I doubt most people would know the MSA20 actually has cache internally.

And that its battery backed up.

Andy
Glenn N Wuenstel
Valued Contributor

Re: msa-20 preformance problem

Another thing to note is that you should take the MSA20s up to the latest shipping firmware. Expect v1.28 soon.
The MSA20 is not just a JBOD like the MSA30, it is actually a smart-JBOD. As stated it contains a controller and battery backed cache.
Glenn
NXS
Valued Contributor

Re: msa-20 preformance problem

I'm having a NAS windows storage 2003 server with 2 MSA20 boxes connected to a 6404 controller on channel A1 and A2.
But when I open the acu I see 2 smartarray controlles (this is normal) and 2 msa20 controllers (??).
The 2 smartarray controllers say they don't have any disks attached. And on the msa20 I can create sata array's.
On 1 of the msa20 controller I have a lot more configuration options (cache settings, rebuild priority,...). On the other I can just create array's an logical volume and he gisves a warning about battery low (is this normal -> problem with the battery in the encloser?).
Another problem I have is that I can't do an expand of a logical volume or array and I can't create an array over the 2 boxes.

I have put the msa20, SA 6404 into the latest FW + windows driver and acu are also into the latest version (smart start 7.30)

thanks Koen
Uwe Zessin
Honored Contributor

Re: msa-20 preformance problem

The MSA20 disk drive enclosure has its own built-in SmartArray controller, so what you are seeing is normal - you have two cascaded SmartArray controllers.
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NXS
Valued Contributor

Re: msa-20 preformance problem

So you can connect an msa20 direct to a scsi and not a smartarray. Bacause the say in the documentation that you can can connect an msa20 to a SA6404.
Can you disable the msa controllers? Is this why you can't extend a logical volume?
Where in the documetation can you find this?

thanks
Uwe Zessin
Honored Contributor

Re: msa-20 preformance problem

I think you are drawing wrong conclusions.

A SA6404 runs SCSI at the back-end, yes, but I have not heard that you can connect the MSA20 to an arbitrary SCSI host bus adapter, sorry. You cannot really disable the MSA20 embedded controller. Even if you connect it to an MSA1500, the embedded SA will encapsulate any SATA disk into a JBOD and present it to the MSA.

* WARNING * WARNING * WARNING * WARNING *

You will loose all data if you move the MSA20 from a backplane SA to the MSA1500 - Dts (DAS to SAN) does not work here!

* WARNING * WARNING * WARNING * WARNING *


Didn't you write that the affected array has a battery low problem? I would fix this first and then look if the problem persists. It is not uncommon on storage controllers that certain functions are disabled when the cache battery has a low charge.
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NXS
Valued Contributor

Re: msa-20 preformance problem

So I always need a smartarray with a msa20. That the controller doesn't see any disks is because the msa controller is between it?
So I only need to configure the msa controllers?