MSA1500 A/A

[Bouzarelos]

Rajiv, here is the show tech_support.

[Rajiv Kulkarni]

Hi,

Appreciate your quick response in sending the logs.

Since the firmware version 7.0 is an active/active one there is one important line to consider in the logs, i.e

"Implicit (automatic load-based) LUN ownership changes are currently DISABLED."

which means that as of now all HOST I/O takes place only through Controller 1.

The other thing which needs to be checked is whether load balancing is enabled on any of the hosts where multipath software is installed. In case of active/active firmware on MSA the recommended option is to disable load balancing on host end and enable implicit configuration on MSA.

Hope this helps..

Also please ensure that the drivers and firmware on all the HBA's are up to date.

Thanks
Rajiv

[Rajiv Kulkarni]

Hi,

Attached zip file containing PDF's which might be useful.

Thanks & Regards
Rajiv Kulkarni

[Bouzarelos]

Rajiv

Load balancing in the side of the hosts is set to none.

In the ACU now we have manually set that all IO goes through right controller as this is what happened when we had Active/Passive Firmware.
However i can't understand why the performance got worse as IO traffic travels the same way. I would expect to be the same and then by setting automatic load balancing performance would be improved.

Almost everyday backup needs about 8 hours to finish instead of 2,5 hours with A/P firmware.

[John Kufrovich]

Bouzarelos,

If you have the Host(HBA) load balancing set to none, your HBA is using a preferred path for IO. And your MSA is running with implicit failover disabled. There is a high probability of proxy IO happening.

If you want to keep "none" for HBA load balancing. I recommend, enabling (Automatic in ACU) implicit failover. This will allow the MSA controllers to move luns based on your perferred path setting on the HBA.

[Bouzarelos]

John thanks for the response

Thats how everything was configured at first. Automatic in the ACU and Load Balance was set to none.

But the problem was still there.

I think HP recommends Load Balance is set to none.

Now HP asked to create a new LUN with stripe size 64k (we use 16k) and make some read/write performance tests.

Could stripe size be such a bottleneck?

I am watching the backup process and i can see it sometimes going like crazy (1GB/MIN) for about 5-10 minutes and then it freezes and falls to 1-2 MB/SEC ~ 60MB/MIN for long time._

[Ola Andreas Windingstad]

hi!

Any progress/ solution in this case,, i have a customer with much of the same symptoms..

I also se in this case that its not mentioned that effective cache in the controllers probably gets reduced to 50% when customer uses active/active on msa1500.
this cuz of now the cache shold be mirrored from both controllers....this can in some cases affect performance


cheers
Ola