HA support of ALUA

steveh · Mon Jul 09, 2012 3:04 pm

When is the new version expected to become available by? I would prefer to wait and not apply beta version to our production servers even though it is working very well.

Mon Jul 09, 2012 3:21 pm

Few weeks maybe.

steveh wrote:When is the new version expected to become available by? I would prefer to wait and not apply beta version to our production servers even though it is working very well.

steveh · Mon Sep 17, 2012 3:33 pm

Now that the new version is available with ALUA support.

What are the steps required to take an existing HA setup and get ALUA working round robin in a VMWARE environment?

Wed Sep 19, 2012 10:08 am

Good question - currently we are working on the corresponding documentation. Stay tuned.
For now I can say that from StarWind side you need to check in "ALUA support" checkbox in target wizard (also you can setup non-preferred path). I have also found good KB article on How-To configure ALUA on VMware side, here it is:
http://kb.vmware.com/selfservice/micros ... Id=1022030

I hope it was helpful

lohelle · Thu Nov 08, 2012 9:09 pm

ALUA is great!
Can ALUA be fine-tuned even more?

If we have 4 1 GbE nics on each node and use the fast SSD SAN as optimized, RR path policy will use 4 paths to the SSD-SAN and have the SATA-paths as backup.

What if we have 1 x 10GbE and 2 x 1GbE NICS on each node (same performance nodes)? Is it possible to implement that RR will use ONE path (10GbE) to each node, and then use the slower 1GbE-paths as backups?

What I'm asking is, does ALUA support optimized PATHS and not only optimized NODES?

Thu Nov 08, 2012 9:20 pm

There's a good chance to see this implemented after upcoming major update. Path priority is a big deal here as everybody tends to have mixed environments these days.

lohelle wrote:ALUA is great!
Can ALUA be fine-tuned even more?

If we have 4 1 GbE nics on each node and use the fast SSD SAN as optimized, RR path policy will use 4 paths to the SSD-SAN and have the SATA-paths as backup.

What if we have 1 x 10GbE and 2 x 1GbE NICS on each node (same performance nodes)? Is it possible to implement that RR will use ONE path (10GbE) to each node, and then use the slower 1GbE-paths as backups?

What I'm asking is, does ALUA support optimized PATHS and not only optimized NODES?

lohelle · Thu Nov 08, 2012 9:27 pm

Great!
I would guess a lot of people is using 1GbE links as backup for 10 GbE.

Thu Nov 08, 2012 9:31 pm

...or don't use them for anything except management.

lohelle wrote:Great!
I would guess a lot of people is using 1GbE links as backup for 10 GbE.

lohelle · Thu Feb 28, 2013 6:18 pm

Did not respond to this one.

We have one dedicated 10GbE switch and a few 1 GbE switches. It would be great if we could run RR, and this would load balance using only the 10GbE links. Than use 1GbE if the 10GbE connection was lost.
Can Starwind with ALUA solve this?

In a 2-node HA-cluster we could it theory get 20 Gb/s reads using dualport nics on our hosts. I know that an extra 10GbE switch would solve this, but it is QUITE expensive.

Thu Feb 28, 2013 6:20 pm

We're working on it, but it is not ALUA based solution. ALUA marks the whole node as preferred, while we need a particular path.
I think the best workaround for now is RR with subset, with 10 GbE marked as active and 1 GbE as passive.

Thu Feb 28, 2013 6:22 pm

No

ALUA makes sense if you have very different from performance point of view nodes and want to handle I/O by one and not split between all of them.

lohelle wrote:Did not respond to this one.

We have one dedicated 10GbE switch and a few 1 GbE switches. It would be great if we could run RR, and this would load balance using only the 10GbE links. Than use 1GbE if the 10GbE connection was lost.
Can Starwind with ALUA solve this?

lohelle · Thu Feb 28, 2013 6:37 pm

OK. I guess ALUA marks the entire NODE as preferred, not a path.

RR with subset would be nice, but at least vSphere can not select more than one specific paths, only one or ALL (or all on one node if using one "optimized" host using ALUA setup)

It would be great if we could select multiple specific paths.

Fri Mar 01, 2013 3:15 pm

Yeah, exactly.

Without ALUA you have option to run Fixed instead of RR, but that will make only 1 NIC active, while all the will wait until first one will get broken.

The possibility to select paths as optimized, not whole node, will be added, but unfortunately I do not have any time frames for now.