Can different drive speeds and sizes be used in a hardware RAID configuration w/o affecting performance

You are missing a step here. When you remove the old logical drives and the physical disk in slot 4, you have to do the following:

• possibly remove Array B
• insert a new disk
• create a new Array B on the unassigned disk
• create logical drives of the requisite size on the new Array B

This can all be done hot in Windows (and usually Linux). The new logical drives will appear upon refresh (F5) of the Disk Manager utility.

Now, you can do this via the hpacucli utility, but it makes much more sense to use the web-based GUI tool, cpqacuxe. You'll understand the steps a bit better there.

Also, I think the continued use of a single-drive RAID 0 array is a bad idea. You do have some interesting options like adding the 72GB disk to Array A and carving out more logical drives. That would help performance and resilience...

Edit: What you're looking to do is not possible without a reboot.

You essentially want to move an array from one server to another. This is possible, but there are rules governing the process. From the HP Smart Array Controllers User Guide:

- *The server is powered down*.
- The array does not have failed or missing drives.
- No spare drive in the array is acting as a replacement for a failed drive.
- The controller is not performing capacity expansion, capacity extension, or RAID or stripe size 
migration.
- The controller is using the latest firmware version.

And the steps to actually perform a move are:

1. Back up all data before removing any drives or changing configuration. This step is required if you are moving data-containing drives from a controller that does not have a cache module.
2. Power down the system.
3. Move the drives.
4. Power up the system.
5. Observe the POST messages:
   • If a 1785 POST message appears, the drive array did not configure properly. Continue with step 6.
   • If a 1724 or 1727 POST message appears, drive positions were changed successfully and the configuration was updated. Continue with step 7.
6. If the array did not configure properly, power down the system immediately to prevent data loss. Return the drives to their original locations. Restore the data from backup, if necessary.
7. Verify the new drive configuration by running ORCA or ACU.

So a poweroff/reboot is an essential step in this process. You can't avoid it for what you're trying to do.

Please take a look at the HP Smart Array Reference Manual and its section on Array Expansion and Migration.

In short, you have the concept of an Array (the assembly of the physical disks) and a Logical Drive (logical RAID arrays within the physical Array).

Your current setup has a Logical Drive of 1TB in RAID 1. Your unused space can be used to extend the existing Logical Drive, or to carve out a new Logical Drive.

If you are doing this using the HP Array Configuration Utility (web interface), you can follow the prompts to expand the array. The space will be available to Windows, but you'll have to handle the partitioning at that level.

This also depends on your controller's setup, though. The Smart Array P212 controller can only do this online if you have a battery-backed cache (BBWC) unit installed.