New ESX server and ISCSI HBA redundancy

[newtoesx2008]

Hi Everyone.

Im Farily new to ESX and ive recently had a play with ESX3.5 with ISCSI storage provided by IET open source ISCSI target software which worked fairly well.

Now the company i work for wants to install 2x Dell ESX servers and connect them to a EMC NS20 via ISCSI for the production environment. Now the ISCSI HBA's ill be using will be Qlogic dual port cards and im wondering if someone whos done this before can give me a rough idea of best practice for setting this up so i have multipath rudundancy. What im wondering is do i team the 2 ports and then run one cable from PortA to Switch A and then PortB to Switch B and then just configure the ISCSI target. This is all very new to me so if someone could give me some Tips it would be much appreciated..even screenshots from VC would be nice.

Thanks in advance.

[crazex · Accepted solution]

You won't need to "pair" them per se. What you are going to need to do is run your ethernet cables to the 2 separate switches. So port A to switch A and port B to switch B. On the backend, your SAN controllers will be zoned to both switches. You'll have to configure your HBA so that it is in the IP range that the iSCSI zoning understands. Now after your SAN admins create your LUN, they should also be able to setup the multipath config for your host and then zone the LUN to it. After this is done, you should be able to scan your HBAs and see the new volume. Also, from what I remember, VMware does not currently support Active/Active connections, just Active/Passive.

-Jon-

VMware Certified Professional

[BenConrad]

You said Qlogic Dual-port so I assume that's a QLA4052C or QLE4062C. One thing to note is that we see the dual-port QLA cards 'reset' themselves under heavy esxRanger backup loads, this causes us to get AsyncIO messages in our vmkernel log (bad). Both ports on the adapter will often go down/up at the exact same moment under heavy load, happens on multiple servers at times.

I've not been able to test this but you might get around this issue by using (2) single-port cards. I think it's a firmware or ESX QLA driver issue. Have a active ticket open with VMWare about this.....

Ben

[newtoesx2008]

Thank you Jon and Ben for your replies. I think i had a picture in the back of my mind of the dual port card coming up in VC and having to configure ISCSI twice but i realize now the dual port card will show up in VC as one device and ill configure the target and that will be that.

Having said that, if i configure one port to switch A and one to Switch B and each switch links to 2x storage processors, if one link goes down i take it the passive path will then be used, is that correct?

I hope to do some reading on this over the next week and try to get as much info as possible, im sure ill get it sorted but the more i learn before hand the better. Thanks for taking time to reply. If anyone else has anything to add please feel free to comment.

[crazex]

The QLogic card, will in fact, show as 2 separate adapters. You'll need to make sure both of these are zoned to the SAN. When zoned properly, they will function as a normal active/passive cluster. Meaning, if you active path goes down, the passive one will take over. This will make more sense once you actually start working with it. It really isn't difficult, provided your SAN zoning has been done properly.

-Jon-

VMware Certified Professional

[newtoesx2008]

Thanks Jon. So i presume then because it shows up as 2x adapters in VC then ill configure each with its own IP address and each i will point to the ISCSI target, as you said ill know more once i actually start configuring the devices. Thanks for your time.

[stubbint]

Hi

You need to turn off async events for the data movers on the NS20.

Using the Web GUI:

Select Data Movers > Parameters tab

Change the Set Paramters box to All Parameters

Find the AsyncEvent parameter for each data mover and change the default value from 1 to 0