HP SSA Performance question

I have a ProLiant DL380 G7 Red Hat Enterprise Linux (RHEL) server with an Smart Array 410i controller.

On Array B (RAID5, 3+1, 450GB drives), I'd like to extend the array onto two 450GB drives.

Are there any metrics to how long array extnend would take?  Does it normally take 15minutes per GB or is that a worse-case scenario?

Also, when starting an array extension, does it affect the performance of the existing array or the server (cpu, memory, I/O response time?  Does it slow performance down?  Are there any reports of losing data or data being inaccessible on the targetted array? 

My customer and I must be well-informed of this before proceeding.

Thanks!

P.S. This thread has been moved from ProLiant Servers - Netservers to ProLiant Servers (ML,DL,SL). -HP Forum Moderator