On Feb 10, 2010, at 8:44 PM, rmumford wrote:

> We're considering moving our stand alone servers and storage nodes to 
> bladecenter, but there's concerns around the limited number of HBAs you can 
> have on a blade. There's also concerns about sharing them with other blades 
> and having tape data mixed with disk data on the same HBAs. Anyone doing this 
> now? If so how does it work, are there any issues etc? Thanks.
 
In my moderately humble opinion, blades offer a lot of useful functionality in 
many situations, but I think it would be a mistake to run a NetWorker server 
off a blade. I have a NetWorker 7.4.4 server on a Dell 2950 with Linux. That 
2950 is connected via four fiber links to a Qualstar tape library with four 
LTO-3 tape drives. It is a real workhorse, but all its slots are full and I 
would like to add another network card to it. I couldn't imagine running a 
NetWorker server on a blade for exactly the reason you stated, limited number 
of expansion slots and I/O bandwidth on the shared blade HBAs. On the other 
hand, using a blade to run a storage node might be a different story depending 
on what the storage node needs to do and what type of backup storage needs to 
be connected to it.

In your decision, try to set up a calculation of how much throughput you need 
in order to complete backups within your backup window, then look at the 
hardware capabilities of the blades you are considering and see if it is up to 
the task. If at all possible, do some real testing with a demo unit before you 
decide to move forward with a blade-based backup server.

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