RAID5 on SmartArray P410i online resize

Solution 1:

You do not have an online option. Online array/logical drive expansion with Smart Array controllers is only available with a battery or flash-backed cache unit. The online features leverage the cache unit heavily during online operations.

See the Smart Array P410 Quickspecs.

Management Features 
Online array expansion (with BBWC/FBWC upgrade)
Online Advanced Capacity Expansion (with BBWC/FBWC and Smart Array Advanced Pack upgrade)
Online logical drive extension (with BBWC/FBWC upgrade)
Online RAID level migration (with BBWC/FBWC upgrade)
Online strip size migration (with BBWC/FBWC upgrade)

In general, it's a good idea to have a BBWC/FBWC unit for HP RAID controllers. It'll certainly improve the write performance on your RAID5 array. See this advisory. Look for HP parts #534916-B21 or #462969-B21.

In order to initiate the expansion of your existing array offline, you can download the HP SmartStart CD image (or use the one that came with the server) and boot into the Array Configuration Utility (ACU) to make the appropriate changes to your array. Follow the array expansion instructions listed in the ACU manual.