SA641/6402 compatibility?

[Andrew_346]

We have a need to very occasionally move a very large file from one data center to another that does not have a very high-speed link between the two. Not to mention, paying to keep a higher bandwidth on the shared networks in these collocation data centers would be a waste of money.

Previously, I had spare slots in servers at both sites that were connected to SA6402 controllers. I would setup a RAID0 on a single 300GB U320 disk and copy the data to it. Then I would drive/fly to the other data center, insert the disk into the other server, reboot it to recognize the new logical disk and copy the data off. Easy, simple and not that expensive.

Well, recently, I had to expand an array on the server at on the the data centers and lost my available slot on that server. However, I still had a two-drive hot-plug assembly in the upper drive bay of this ML530G2. It wasn't connected to a controller (had been disconnected a long time ago) so I ordered an inexpensive SA641 to use with these two hot-plug bays.

I recreated a new R0 array with the 641 and sent it back to the primary data center to wait for when a large data transfer would be needed. The server at that site recognized the array and adopted it, just like when I used to use the 6402 controller. No problem.

Well, this weekend, I need to get that large file down to the secondary data center again. So I copied the file to the disk (connected to the 6402 controller), retrieved it from the data center and tried to reboot the other server with the 641 controller to bring that disk online.

It failed to recognize it. So, I changed nothing, erased the array that I had expanded on that server (the data was bad anyway) and then made a slot available to connect that 300GB drive to the 6402 controller. It failed to see it as well.

After some trouble shooting on that server, I realized that I could get the 6402 controller to adopt a RAID0 array from the 641, but not the other way. An when I had attempted to reconnect the array back on the 6402, it's RAID info was gone. It would never work again.

And if anyone asks, the configuration was cleared on the each controller. It never had an orphaned or failed array before trying the next step.

Any ideas? Are these controllers simply not going to be compatible both ways? Will I need to return the 641 and purchase another 6402?

[KarloChacon]

hi Andrew

it seems like 6400(6402) supports RAID from 641 but not 641 supports from 6400

http://h18004.www1.hp.com/products/servers/proliantstorage/arraycontrollers/smartarray6400/questionsanswers.html

Can other Smart Array controllers be easily upgraded to the Smart Array 6400?
Yes, this is the Smart Array Advantage! Upon reaching the limitation of the SMART-2SL, SMART-2DH, SA221, SA3200, SA4200, SA431, SA532 or the SA5300, customers can easily replace them with the SA-6400 to increase data performance, data availability and data capacity. Just upgrade the drivers, shut down the server, replace the old controller with the new controller, and the new array controller will seamlessly recognize the disk drives, RAID configuration and data.

6400 is backward compatible but 641 is not
i don't know this word "forward compatible"

so you need to buy a 6402 card

some links
http://h18004.www1.hp.com/products/servers/proliantstorage/arraycontrollers/smartarray641/index.html?jumpid=reg_R1002_USEN

http://h18004.www1.hp.com/products/servers/proliantstorage/arraycontrollers/smartarray6400/questionsanswers.html

regards