HP Lefthand VSA 2-Node Question

[jjahns]

My environment is:

• 2x ESXi Hosts w/ 2 TB each
  
• 1x  vCenter VM
  
• 2x VSA VMs (1 per host)
  
• 1x ISCSI volume from VSAs (1.5 TB each in RAID 2-way mirror)
  
• 1x Failover Manager running on local storage on one of the hosts.
  

My question is that since I've got 2 VSA nodes and 1 FOM, what happens if the ESXi host with the FOM and one of the VSAs fail?  Will the other VSA take over what it needs to in order to successfully failover?  If not, what do I need to do to fix that?

I've got to make this environment work for what we have, so any information you can give helps.

[eddie563]

Lets start by hopefully jogging your memory,

for the HP VSA to be highly available it requires 2 of the 3 to be available, i.e. for a failover to work, you need to have:

FOM + VSA 1

FOM + VSA 2

VSA1 + VSA 2

if you lose 2 of the 3 then there can not be failover. if you are lucky enough to lose the host that holds only 1 VSA then you will be fine, if you lose the host with VSA + FOM, i would start clearing out my desk He He !

the reason this wont work is that the heartbeat between all 3 VM's needs to tell the others that one has gone,

I tested this to death before going live in production, what im looking at now is migrating the VSA to larger storage on a seperate host.

in my situation i have 2 server rooms in seperate areas on my site and also an NEC (Network Equipment Centre), 3 different buildings

i have

VSA1 in Primary

VSA2 in Secondary

FOM in NEC (low spec server)

so if i lose a host then the other 2 will run fine and the same if i lose the FOM.

if you are running this in one server room you will definately need 3 servers to be HA, other than power or network faults !!!!

i would suggest if you can squeeze a little money or recycle an old server and depending on your licensing,

host 1 - VSA1

host 2 - VSA2

host 3 - FOM + vCenter VM as if you lose the vCenter, you lose VM HA and losing VM HA and VSA HA, i dont believe can be a good thing.

its my first post here, if you feel i have helped you any please award as you see fit, if you need anymore help, just reply, i have been where you are and hopefully i can save you some time an effort from my experience.

Regards,

Eddie.

[amvmware]

You would have to be pretty unlucky for this situation to occur - I would put the management appliance VM in a different location. The VM can run on VMware server - so you don't have to run it on the same hosts as the production VM's.

As has been stated the failover works on a majority vote method so a san node can determine if it is isolated or not - If the node can communicate with the FOM then it is not isolated as there are 2 votes - if the node becomes isolated due to network failure then the node will recognise it is isolated and power them down.

As far as the FOM is concerned it has a node failure and will instruct the node it can communicate with to power up the VM's that it deems to be isolated on the other node.

If the FOM fails then my understanding is the nodes will try to ping each other after the FOM has failed and if they can still communicate then they will function as normal. If you lose a node as well as the FOM at this point then depending on how you have configured the nodes the VM's will remain powered on or power off on the only active node remaining - but this is because it thinks it is isolated and will perform accordingly.

Mitigate the issue from occuring - put the nodes in different racks, redundant switches, management VM in a different location to the nodes on a host that is not running production VM's.

[SantiniStorMagi]

I know this thread is a bit old now but thought I would update it.

StorMagic Inc, have actually gotten around your little dilema. Our SvSAN, Storage Virtual Appliance (SVA), No longer requires the FOM, NSH, Quorum, 3rd Point of contact server (Sorry it goes by so many different names).

This additional hardware is generally associated with all SVA's, but stormagic is the only one at the moment that does not require this, it also does not require vCenter locally to achieve high availbility, this means that you can also achieve HA on Free versions of ESXi and on ESXi Essentials making it even more cost effective.

As I'm sure you can imagine the additional functionality has become very popular, especially for mult-site environments.

You can find out more about SvSAN on our site, just have a look at http://www.stormagic.com/SvSAN.php

We also did a webinar recently which covers ROBO environments, it has a live demo of SvSAN as well as more info on not requiring the FOM.http://stormagicuk.wordpress.com/2011/11/14/webinar-solving-challenges-achieving-high-availability-i...

Feel free to get in touch if you have any questions.