Expanding an array
Expanding an array
The Expand Array option lets you expand the capacity of your existing array by adding more drives or adding sub-arrays.
Using a RAID 5 array example, adding more drives to the array lets you increase the capacity of that array. If you add additional sub-arrays it requires the exact number of drives to be available for the original sub-array. For example, if you have an array composed of 4 data drives and 1 parity drive, you must have a minimum of five drives available to be able to add at least 1 sub-array.
When you view the array configuration information, the RAID type and number of drives are displayed. These drives are depicted as data drives plus parity drives. In this example, it would be displayed as “4 Drives (3 +1)” which indicates the array/sub-array is composed of 4 drives of which 3 are data drives and 1 is a parity drive. If you were to add 1 sub-array to this particular configuration, the resulting display would be “8 Drives (6+2)” in which case you now have 6 data drives and 2 parity drives. Your RAID 5 array now becomes
aRAID 50 array because it’s composed of two sub-arrays, each sub-array has three data drives and one parity drive.
If you are expanding a RAID 50 array by adding drives to the array, you must add an equal number of drives to each sub-array.
The process of expanding the array by adding additional sub-arrays allows for quicker recoveries in the event of a drive failure in any one of the sub-arrays, and the time required to rebuild the array is significantly shortened.
To add more drives to your existing arrays, refer to “Adding additional drives” on page 54.
To add more sub-arrays to your existing array, refer to “Adding additional sub-arrays” on page 57.