I recently needed to expand a RAID array on my HP ML350 G5 test server from a 5 drives RAID 0 configuration to a 6 drive RAID 5 configuration so that I could have redundancy as well as performance. My server has a HP P400 Smart Array Controller, but this process is pretty much the same on all HP RAID controllers used in the 300 series or higher servers.
To expand or migration a RAID set on a HP RAID controller is a two step process. Firstly you must expand the array to include the new drive. The second phase is where you migrate the array to take advantage of the space on the new drive. During this 2nd phase you have the option to also change the Stripe size and or the RAID type based on the number of drives you have installed in the system. This procedure below shows you how to do this process.
- Ensure you have a complete backup of all data on the RAID array you plan to expand.
- Ensure that you perform the expansion and migration at a time of low system use, ideally have all users off the system if possible.
- Install the additional drive into the HP servers drive bay
- On the server itself, login as an administrator and then login to the HP Array Configuration Utility.
- Ensure that the new drive is not part of any array.
- Select the existing array you wish to expand and then “Expand the array”.
- Select the new drive that you have added to the system and confirm that you wish to expand the array.
- The array expansion process will now commence. This will take time – anywhere from an hour to a few hours dependant on the size of the drives and the load on the system.
- Once the array is expanded, close the HP Array Configuration Utility and reopen it – this is due to the fact that some information only refreshes correctly when you open the Array Configuration Utility.
- Now navigate to the Array you wish to migrate, select the Array and then “Migrate Array” from the right hand menu.
- You will select the applicable RAID type you wish to migrate the array to, ie RAID 5 in this instance, and also select the Stripe Size. Do this and select “OK”.
- You will see a screen similar to the one below – note that is is “Transforming 0%”. The Array will take some time to expand. It is recommended that you do the expansion at a time that is low load on the system to ensure it does not interfere with normal system operations. Performance during this time WILL BE SLOWER than normal due to the RAID expansion.
- After the RAID expansion is complete, you will see the screen return to normal.
- Close the Array Configuration Utility and reopen it. Expand the Array and then select the Logical Drive. Select the More Information button and you will see the screen below. This is after around 8 hours. The RAID migration is complete, and the background Parity Initialisation is in progress (it’s at 44% right now). This means that the process is not complete and disk performance will still be adversely affected. Wait a little longer.
- Your array expansion and migration is now complete. All data should be in tact and things should be working as you expected them to be.
- Close the Array Configuration Utility and enjoy your new, expanded and protected drive 🙂