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using FOM

 
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pob579
Advisor

using FOM

Hello,

I just started with P4000. I created VSA VM on each of 2 Hyper-V nodes (later planning to test in vSphere too).

Here are some questions that comming up... I know I have to read more but sometimes quick comprehensive answers save a lot of time and make the life easier.

 

1. I installed the latest version of VSA - 9.5. The CMC in the package is 9.5 too. After installation of CMC it shows updates available. When click download it downloads 6GB+. Initial installation files for CMC is just 84M.

How come that update for 84M app is 6GB?

 

2. Before creating first managed group best practice say I must have FOM for full redundancy and etc.

Where I should install FOM? on each Hyper-V node or on one?

 

Other questions comming... :)

 

Thanks.

Michael.

 

 

9 REPLIES 9
Bart_Heungens
Honored Contributor

Re: using FOM

Hi,

 

That initial 6GB download is typical since the CMC downloads (once) all updates of all P4000 products, hardware and software version...

 

The FOM is only ncesessary in case of split brain situations... If you have an even number of storage node's (VSA or physical, picture stays the same), in case there is a network issue in between them, U will need a majority to decide which site survives and can keeps its data online (like with server clustering).

 

So U only need/want/cativate 1 FOM on a third location in betwwen somewhere, if not possible activate it in the 'best protected' server room...

 

 

Kr,

Bart

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pob579
Advisor

Re: using FOM

Bart,

just to clarify...

as I mention in my initial post. I have 2 nodes with VSA installed on each. I clearly understand that VSA just simulates physical storage.

Yes, want to test network RAID with 2 storages.

I want to simulate one storage failure and Hyper-v clustered shared Volume host (just to pull power off)

So, I understood that I need FOM for managing storage failover (2 or more storages). Correct?

 

And the question is where I have to install FOM. Is it VM package or I need to install a vserver and then install FOM app?

I understood what you explain about third site (in between).

In my situation there are 2 NODES in one server room in test environment.

 

Thanks.

Michael.

Bart_Heungens
Honored Contributor
Solution

Re: using FOM

Hi Michael,

 

If the 2 storage nodes (VSA) are in the same room, then the FOM can be installed also in the same room off course. This 3rd site is only when U have 2 server rooms for DR purposes...

 

If U have 2 VSA's and there is a network issue between the nodes (split brain), the VSA's will stop publishing the LUN's to the servers, for data and self protection reasons. At that moment the FOM will decide which of the 2 VSA's will keep their I/O active, being the VSA which he can communicate with...

 

FOM is just another VM that can be installed (often seen) on a laptop with VMplayer or so on it... Does not need that much resources...

 

It can be also on 1 of the 2 Hyper-V hosts, but then off course that particular host should not be shut down off course. That is why a third PC/laptop/old server can do the trick also...

 

 

Kr,

Bart

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pob579
Advisor

Re: using FOM

Thanks Bart!

RichCurl
Visitor

Re: using FOM

You had stated "FOM is just another VM that can be installed (often seen) on a laptop with VMplayer or so on it".  Does that mean that the FOM unit is typically turned off and not started until a failure occurs?   I'm in the process of installing and trying to wrap my head around fail over manager and the virtual manager. 

 

Rich.

Bart_Heungens
Honored Contributor

Re: using FOM

Hi,

 

No, FOM should be running... The main difference between the Vurtual Manager and the FOM is that the Virtual Manager is a manual action to start the Virtual Manager in case of issues to regain quorum... This means that U have a certain time of downtime...

 

To avoid this, the FOM is there to be always online and keep quorum without loss of I/O in case of issues...

 

 

Kr,

Bart

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RichCurl
Visitor

Re: using FOM

Thanks, that cleared it up for me. 

 

Rich.

Sainyam
Occasional Visitor

Re: using FOM

Hello,

 

I want to deploy FOM on Hyper-v enviroment, Can anyone provide me detailed steps for installing it, Since I am new to this.

 

Thanks in advance.

jingxi02
Occasional Visitor

Re: using FOM

For the FOM node, you DO NOT want to deploy it along with and other VSA node.  In the other word, don't put it in the same physical server that is running the VSA node.  You just deploy it outside the Hyper-V to ESX server.  Put it in another virtual host.  The key is when you loss any of your VSA node, you need to have the remaining VSA node and the FOM node to fail-over the disk I/O.  If you put the FOM on the same Hyper-V host with any of your VSA node and this Hyper-V host failed, you are going to loss one VSA node as well as the FOM all together.  It results the remaining VSA node won't be able to fail over and take over the storage I/O.