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ESXi Datastore High Availability / Fault Tolerance

Right now we have 3 servers, all with Enterprise Plus licenses, all connected to a single iSCSI SAN.  When it comes to redundant server resources, ESXi has us covered, but there's one issue I can't get by and that is the single failure point of the SAN having the potential to bring down our whole VM environment.

How does VMware handle/avoid this scenario?  
Do we have to get a secondary/redundant SAN?

Let's say I have 3 servers, all with the OS Raid 1, and then each with a 5TB capacity raid for storage.
Is there a way set up each 5TB array as HA/FT storage? perhaps storing VMs independently of the server hosting each VM?

For example, let's say I have a VM and 2 ESXi servers (Server A and B).
The VM is hosted on (Server A) and the storage is on (Server A Storage)
If server A's datastore goes down can (Server B Storage) be set up to take over the data?
It doesn't matter if A or B handle the resources.
Is this possible?

I'm trying to figure out how to HA/FT storage without having to have 2 SANs.
1 Solution
costanosNetwork EngineerCommented:
I believe the only way to eliminate having a single point of failure in this configuration is a secondary SAN..  

I am in the same boat but the client can not afford to pay for a second SAN.

We are basically running a 3 2 1 config.  Everything is set up for avoiding failure except the single SAN.
Regards to your example question, it is possible now and simpler to achieve if you use the VMware Virtual SAN, which VMware launched few days ago, but there are new set of requirements.

Here is more info.

Other than that to do  datastore High Availability / Fault Tolerance you will need a 2nd SAN.

There are ways to reduce the single failure point if you do not have budget to purchase secondary/redundant SAN?  You need to make sure that you have redundancy on your iScsi switch, redundancy controller, RAID Level for your SAN storage..etc

Hope this helps.
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