Increasing the Storage Capacity on a Pegasus R(x)/Pegasus2 R(x) Series

The storage capacity can be increased by purchasing higher capacity physical drives. In addition, Promise recommends that the drives that will be utilized have been cross-referenced with our Pegasus Compatibility List found on our Promise Support Site.

Pegasus Compatibility List V1.17

Pegasus2 Compatibility List V2.10

If you’re inquiring about upgrading the storage capacity for an array, you should purchase and replace each drive with the same capacity per each physical drive slot. If you replace a drive that has a larger space capacity, the drive will reduce its capacity to the smallest drive in the array.

For example, if you have a Pegasus2 R4 with 4 X 2TB drives and replace only one slot with a 4TB drive, the drive will actually allocate and equate to 2TB as the other three slots are configured with 2TB drives in the array. The remaining 2TB will be unusable. Therefore, you will not see an increase in the logical drive’s size after you’ve successfully rebuilt the previous drive’s sequence to the new drive.

Promise recommends to execute the following when upgrading the physical drive capacity on a Pegasus R(x)/Pegasus2 R(x)

1. Execute a backup of the data from the Pegasus volume to another destination volume.
2. After the data has been successfully copied to the destination volume, unmount the volume and shutdown the unit.
3. You can shut down the Pegasus unit by accessing the Pegasus Utility or accessing the CLI (OS X).
3A. [OS X]
Shutdown the unit by opening the [Pegasus Utility > Subsystem Information > Shutdown]
3B. You can also open a Terminal session (OS X):

HostName:~ user$ promiseutil
cliib> shutdown -a shutdown

3C. [Windows]
[Pegasus Utility > Admin > Subsystem Information > Shutdown]
4. After the unit has been shutdown, proceed in installing the new physical drives.
5. Turn the Pegasus unit back on.
6. Once the Pegasus unit has booted, proceed in configuring a new array and logical drive.
7. Once you created your new array and logical drive, proceed in copying the data from your backup.

If you have any questions or concerns, please open a support request via