Comments on: Lefthand SAN – Lessons learned

By: Greg

Greg — Sat, 16 Jul 2011 16:35:06 +0000

I am new to lefthand and need a some clarity about when the fail over manager is needed. If I have 2 Node VSA in the event of a failed node will the failover occur with automatically?

By: Aart Kenens

Aart Kenens — Tue, 12 Jul 2011 20:53:39 +0000

Hi Frank,

Did you ever checked Ken Clin’s his question?
I simulated his question and I can see this behavior on our iSCSI switches.

We made a support ticket with HP but so far we have no solution, yet …

regards

By: Lessons Learned about Multisite Clustering using HP StorageWorks P4000 SAN Solutions « Stretch Cloud – Technology Undressed

Tue, 03 May 2011 07:13:44 +0000

[...] Lefthand SAN – Lessons learned [...]

By: Jeffrey Wolfanger

Jeffrey Wolfanger — Sat, 08 Jan 2011 21:02:36 +0000

Frank-

I wanted to say “thank you” this article helped bring me up to speed very quickly. I am currently looking at additionally changing a Lefthands raid level after implementation into a cluster. This should be interesting…I find this an extremely interesting feature.

Cheers,
Jeffrey

By: ratgeber flirten

ratgeber flirten — Fri, 22 Oct 2010 13:26:08 +0000

denke auch

By: paul hutchings

paul hutchings — Sat, 16 Oct 2010 18:03:35 +0000

Great article

We’re looking at a basic two-site, single-subnet multi-site cluster.

The current thing I’m trying to figure out is what if the iSCSI link fails, but the host(s) and primary LAN are still up?

HA doesn’t seem to cater for the storage disappearing from a host but the hosts still being able to see one another?

By: Russ Couch

Russ Couch — Wed, 22 Sep 2010 02:49:40 +0000

Hi Frank

Interesting article thanks. We have a multisite LH installation since July 2010 and I have a question, pretty much the same as Rod Lee above. At the moment our ESX hosts are accessing some LUN’s across our intersite fibre link because the gateway IPs are hosted on the other site. Luckily its pretty a quick link and to date I use the rebalanceVIP command to try and shift the gateway IP between sites. This is pretty unreliable and can cause micro outages to the LUN in question. Is this really the way it should be working or is there another way around this?

I notice vSphere 4.1 is going to support a proper DSM but unfortunately Data Protector doesn’t support that yet.

Thanks
Russ..

By: Ivan

Ivan — Thu, 08 Jul 2010 07:20:06 +0000

Hoi Frank,

I was kinda curious if you have found out how ALB really works.

Thanks!

By: Martin W

Martin W — Tue, 06 Jul 2010 20:28:39 +0000

Lefthand does have an interesting design, one that should be possible to build yourself by using regular servers with some disk and some open source software. The design isn’t that complicated after all, just basically a network raid. A lot of this stuff is probably using open source software already in the lefthand products, as evident by the obviously linux based bonding..

It’s time for a solid open source SAN!

By: Rod Lee

Rod Lee — Mon, 28 Jun 2010 14:05:38 +0000

Hi – first thanks for a great article – we are thinking of implementing LH and have a couple of questions I hope can be clarified.

In a single cluster two site implementation the nodes are separated by a wan link – how do I ensure that a lun created on the cluster is served locally to the server connected to it? I am guessing this would be done by LH knowing that the mac address of the initiator is in the arp table of the switch the node is connected to and that therefore that node should be used for the connection.

And

Data is replicated across a wan in a single cluster two site implementation are only the changed disk blocks replicated or is an entire file replcated?

Thanks