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I am in the process of sourcing our company's first SAN as we have the need for high availability/shared storage. I have noticed fibre channel switches are extremely expensive, and for redundancy we will require 2 of them, costing around $12000 on the low end. The SAN we are looking at (HP MSA 2040) comes with 8 fibre channel ports, and we will only require 6 total (2 per ESXi server * 3).

So my questions are:

  • Can we directly connect the SAN to the server HBA and skip on the switches?

  • Will we still be able to use vMotion and High Availability using direct connections from all servers?

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Others have replied that you can, so I won't try to answer. However, have you looked at host HBA prices also? They are expensive too. If cost is such a problem and with no existing investment, have you thought about going FCoE or iSCSI? – Law29 Mar 13 at 17:48
    
It's not that cost is a huge issue, it's just that I can think of better ways to spend $12,000 than on FC switches if they aren't required. FC is the tried and true protocol for ESXi and was the first shared storage protocol around for this kind of thing. Anything running over TCP/IP has to be encapsulated and there is overhead, withdrawing from performance. – WargleBargle Mar 18 at 0:06
up vote 12 down vote accepted

You can use multipath FC connections from your servers to the MSA2040 without the use of a switch.

You would connect your HBAs on thee servers to each of the two controllers on the MSA. The MSA2040 was designed for this, and this is a fully supported cabling and VMware host design.

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thank you for the link. I assume the only node I need is the actual array controller (MSA 2040) and not any additional drive enclosures? The literature makes it sound like the additional drive enclosures are only for expansion, and that the MSA 2040 can hold 24 bays itself. – WargleBargle Mar 13 at 5:19
    
That is correct. The MSA2040 and the internal bays should be enough if the capacity meets your needs. – ewwhite Mar 13 at 5:20
    
Edit. I linked the wrong cabling guide. This is the correct one. – ewwhite Mar 13 at 5:39

Can we directly connect the SAN to the server HBA and skip on the switches?

Yes, no problem here.

Will we still be able to use vMotion and High Availability using direct connections from all servers?

Yes.

What you'll be losing out on, though, is the ability to leverage multiple fibre paths from your HBAs to your SAN, meaning that if your HBAs fail, or if the cable fails (or gets accidentally damaged/unplugged), or if the HBA on the SAN fails, there is no redundancy in place to protect you from downtime. It sounds like you're well aware of that, though.

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2  
The MSA 2040 model we are looking at is a dual controller model, would I be able to run 1 fc connection to each controller? We plan to install 2 HBAs per host. – WargleBargle Mar 13 at 5:10
1  
Yes, certainly. – EEAA Mar 13 at 5:13

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