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pinkerton
Enthusiast
Enthusiast

Is a FC-switch required to connect ESX 4.0 to a FC-SAN?

Hi,

another question. We're planning to make use of a HP StorageWorks MSA 2000fc G2 Fibre Channel SAN to connect

to ESX servers to it. The MSA2000fc G2 comes with two controllers and two ports per controller.

In theory, we could connect two ESX servers directly to the SAN controller's ports without the need to install a switch.

However, our distributor told me that at least in ESX 3.5 this wasn't possible as ESX considered such configs as

Direct Attached Storage.

Does anybody know something about this? Shouldn't it be possible to use such a configuration without the need to

install a FC switch? Do any of you guys use such a configuration?

6142_6142.JPG

Thanks

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AWo
Immortal
Immortal

I don't know how ESX sees SAN storage which is attached without a switch, but if it see's that as local storage that shopuld be fine.

But IMHO, I would strongly advice to use a switch. Otherwise you can't use many of the features which requires shared storage and a SAN is referred to as shared storage usually. But to have it shared you need a switch (O.K., theoretically there's still the arbitrated loop configuration, but in fact I'll never saw this one to the front-end servers in a datacenter, yet. And O.K. you seem to have two hosts connected; that may work, as well).

You may also run into trouble whan you need to add new storage to the server, as you may have no ports free anymore. Again, you'll need a switch.


AWo

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marcelo_soares
Champion
Champion

MSA 2000 seems not compatible with ESX, this is the first thing you may consider (maybe you will not get all funcionality/support for this device). Second, connecting SAN directly to ESX without FC switches is never supported, as it can generate path thrashing (if your SAN is active/active, this problem should not occur, but if it is active/passive, you will not be able to share the LUNs between both ESXs, or the access will be too slow).

Generally, I never suggest it.

Link for the HCL to check compatibility: http://www.vmware.com/go/hcl

Hope this helps your decision...

Marcelo Soares
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Oczkov
Enthusiast
Enthusiast

First, for vSphere 4 only MSA2012sa is supported at the time of the post writing. You should expect FC and iSCSI models comming soon on the support matrix for storage.

Second, if you are going to use ESX 3.5 (U4) the configuration proposed is supported by VMware (direct attach) for MSA2312fc (firmware: M100R06 and M100R18) and MSA2324fc. Another array known to be supported in a direct connect mode is EMC CLARiiON AX4-5, which you can consider. Now it is only supported in DA for ESX 4.0 (not ESX 3.5, but I remember that previously, at least for some time, it was). Always consult: http://www.vmware.com/resources/compatibility/search.php

Regards,

Oczkov

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