2010-04-17 10:55 PM
Not much really....the sole exception is if you have shelves out there with original ESH modules you'll need to sell/install ESH4 modules in their place before going to ONTap 7.3.x or a newer 31x0 head.
2010-04-21 07:08 AM
I agree with aborzenkov but as always it depends on your situation, so maybe Andrew is also right: of course you can replace the ESH2 modules of an DS14mk2 with ESH4 controllers - but the backplane of the shelf probably still is not able to handle 4GB, and the disks of course also have a 2GB interface. So it is questionable if you will get any performance benefit of inserting ESH4 or if it is just a waste of money. But perhaps you have to, because this ESH2 is the only remaining controller in a 4GB loop?
I had the same issue long ago with DS14mk (ESH) and DS14mk2 (ESH2)...