The M-Series appliances leverage RAID 1 for data redundancy in the event of disk failure. Therefore, the pair of drives in a RAID 1 array need to be identical. However, you are free to mix drive capacities across different RAID 1 arrays. For example, the drives in the A1/A2 RAID 1 array can be 1TB drives, and the drives in the B1/B2 RAID 1 array can be 2TB drives.

Because each drive pair (A1/A2 for example) is in a RAID 1 array, the total storage capacity is half of the total drives installed. For example, if an M-100 appliance has 2TB drives installed in drive bays A1/A2 and B1/B2, the A1/A2 array provides 2TB total storage and the B1/B2 array provides another 2TB for a total of 4TB.

You don’t need to take the M-Series appliance offline to expand the storage when adding drives to an M-Series appliance that is already deployed. When the additional drives are configurable and available, the M-Series appliance redistributes the logs among all available drives. This log redistribution process happens in the background and does not impact uptime or the availability of the M-Series appliance. However, the process does diminish the maximum logging rate. The Redistribution State column (

Panorama

Collector Groups

) indicates the completion status of the process as a percentage.