HPE EVA Storage

EVA6000 MPIO load balancing question

 
Alex_317
Occasional Contributor

EVA6000 MPIO load balancing question

We are running 2 DL380 G4 in MS active/passive cluster attached by 2 Emulex HBA's. Currently we have "none" set as the load balancing policy, is one of the settings better for Exchange performance.
9 REPLIES 9
Jacky Wing
Regular Advisor

Re: EVA6000 MPIO load balancing question

I never calculated the time or got any performance results.

However logically i guess setting SQR for exchange data files is good and set up SQST for log files.
Timothy Cusson
Valued Contributor

Re: EVA6000 MPIO load balancing question

You may want to verify Microsoft cluster specifications, I don't think it supports load balancing, you must leave it at none.

Tim
Alex_317
Occasional Contributor

Re: EVA6000 MPIO load balancing question

After reading a few things, yes you are correct that load balancing in MS Cluster is not supported but they keep refering to the fack that MS Cluster and MPIO are two very different forms of high availability and can be used to max your high availability. Strange!

If my 1 active cluster siezes the 4 drives running on the SAN I do not see how the Cluster would care what the disk sub-system is doing in regards to MPIO as long as the drive is available to take. I am probably thinking this might only apply to active/active clusters.
Uwe Zessin
Honored Contributor

Re: EVA6000 MPIO load balancing question

MSCS and load balancing (LB) are related, because MSCS uses SCSI-2 reservations by default.

MSCS and LB are supported on some versions of the MPIO, but you do need to change all of your cluster nodes at the same time to use a different reservation style. I don't have the details at hand, but you really want to check the MPIO's release notes.
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Alex_317
Occasional Contributor

Re: EVA6000 MPIO load balancing question

Here is the answer from the readme on the lastest version of full featured MPIO for EVA. It can do it with this version.

****************************************************************************************

VI. HP MPIO Full Featured DSM Configuration Settings

1. Load balancing in Microsoft Cluster (MSCS) Environments:

This version of HP MPIO Full Featured DSM for EVA4000/6000/8000
family of Disk Arrays supports I/O load balancing in Microsoft
Cluster environments with the help of persistent reservations.
Load balancing in Microsoft Cluster environments is supported
only if (i) all nodes in cluster have this version of the
product installed (ii) the DSM on all nodes in cluster is
enabled to use persistent reservations and (iii) the disk
array is running a firmware that supports persistent
reservations.

For details on firmware revisions that support persistent
reservations, please contact HP support.

The Load balancing feature in Microsoft Cluster environments
is disabled by default in the DSM.

* Enabling load balancing in an MSCS environment:

The following operation needs to be performed on all the
cluster nodes, one at a time:

* For new and upgrade installations of the DSM, load
balancing can be enabled during installation by choosing
the "Enable Load Balancing in Cluster" option in the
Configuration Settings window of HP MPIO Full Featured DSM
for EVA4000/6000/8000 family of Disk Arrays Setup.

* Alternately, this option can be enabled at any time later
by following the sequence below:

- Open an Explorer window and navigate to the DSM
installation directory.

- Double-click the file hpeaadsm_pr_on.reg and follow the
onscreen instructions.

This file will make the following entry in the registry:
Under "HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\hpeaadsm\Parameters", a value named
"UsePersistentReservations" (DWORD) is set to 1.

- Reboot the system for the changes to take effect.

* Disabling load balancing in an MSCS environment:

The following operation needs to be performed on all the
cluster nodes, one at a time:

- Open an Explorer window and navigate to the DSM
installation directory.

- Double-click the file hpeaadsm_pr_off.reg and follow the
onscreen instructions.

This file will make the following entry in the registry:
Under "HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\hpeaadsm\Parameters", a value named
"UsePersistentReservations" (DWORD) is set to 0.

- Reboot the system for the changes to take effect.

IMPORTANT: The Load Balancing in Cluster feature setting in the
DSM must be consistent across all cluster nodes.

* Persistent reservations clear utility (hpprutil.exe):

If there is a stray persistent reservation on an EVA device,
the device may not be accessible from host systems. The
persistent reservations clear utility can be used to remove
such reservations from the device, thereby allowing host
systems to access the same.

This utility is located on the installation media (CD). It
is also copied to the installation directory by Setup. For
more information on using this utility, type "hpprutil /?" at
the command prompt.

WARNING: Using this utility incorrectly can cause serious
problems that may result in loss of data and/or incorrect
operation of the Microsoft Cluster Sevice. HP cannot guarantee
that problems that result from the incorrect use of this
utility can be solved.
Rudolf Stark
Advisor

Re: EVA6000 MPIO load balancing question

Hello,

does this mean, that MPIO load balancing is supported on EVA, and EVA supports persistent reservations? What are the minimum XCS/VCS-Firmware-Versions?

Thanks and regards
Rudolf
knoxvegas
New Member

Re: EVA6000 MPIO load balancing question

Has anyone got SQR working with MSA 1500 with MSCS? I have a MSCS set up with two MS 2003 servers. I'm getting an error that it's not supported. Please help.

Uwe Zessin
Honored Contributor

Re: EVA6000 MPIO load balancing question

Did you switch both servers to use persistent reservations?
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knoxvegas
New Member

Re: EVA6000 MPIO load balancing question

How do you do it with MSA 1500? I've seen an article on how to do it for both generations of EVA. Thanks for the response.