IBM EXP 2500 enclosure

I got an IBM EXP 2500 enclosure with dual sas ports.
My IBM system x server has a raid card M5025 SAS/SATA controller.
My question is can I connect the IBM Exp2500 enclosure to two IBM system x server and create a cluster with VMware as it got two port on IBM exp 2500 enclosure.
Please advice.
jacksch4820Asked:
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andyalderCommented:
Sorry, my bad. As far as I can find out it's only single connected, the EXP2500 only has 2 SAS ports, one to connect to the host and one to daisy-chain to a second enclosure.

Don't have a picture of the back to confirm, if it can be dual connected there will be diamonds on two of the SAS connectors on the back.
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andyalderCommented:
Unless you have the option to disable all caching on the RAID controller you cannot use it in a shared storage cluster. You also cannot have RAID enabled on the controller. If you can do without RAID it may be possible to make a cluster with a single disk by putting the controller into HBA mode. Normally you would buy dumb HBAs for the servers with RAID performed inside the shared disk enclosure.

Think what would happen if cache was enabled, server 1 will read and write to what it thinks are the disks but the controller will cache this so server 2 will not see the changes since they are in the local controller's RAM on server 1.
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jacksch4820Author Commented:
okay thanks so why does the IBM exp 2500 have dual ports please advice
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andyalderCommented:
Two ports so that you can redundantly cable it to a single RAID controller plus 8 lanes of bandwidth rather than 4.
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jacksch4820Author Commented:
wil it be active/active or active/passive please advice
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jacksch4820Author Commented:
great thanks andyalader
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plomakoCommented:
Some comments regarding this topic were not true.

EXP2500 has two input SAS ports and one output SAS port for daisy chain connections.

BUT only one input port can be used.

See page 5. of following IBM document:
http://www-01.ibm.com/common/ssi/rep_ca/0/877/ENUSZG11-0300/ENUSZG11-0300.PDF 

"An EXP2500 can be connected to only one SAS Connectivity Module, even though
the environmental services module has two upstream (initiator) SAS ports. The
EXP2500 does not support zoning of the disk drives within the enclosure and
cannot be shared among multiple SAS Connectivity Modules."

It looks that IBM developers had a great fun confusing customers with double ports while only one can be used...
BTW. I studied hundred pages of IBM manuals and there is only this one sentence about it. No drawing, nothing.
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jacksch4820Author Commented:
thanks plomako for u input
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