Adaptec 5325301656 Administration Guide - Page 60

RAIDs of a single RAID allows administrators to expand a volume without reconfiguring RAIDs and allows users to continue working as usual with no interruption. Grouped RAIDs must be the same type; you can group two RAID 1s or two RAID 5s (e.g., you cannot group a RAID 1 and a RAID 5). Note Only RAIDS of the same PE (physical extent) size can be grouped. If you are growing the volume on one RAID to use free capacity on another RAID, you will only be allowed to select from those RAIDs that can be grouped. Also consider the following: Adding an Expansion Array In a common scenario, a Snap Server 520 configured as a RAID 5 is nearing full utilization. The administrator decides to add a SANbloc S50 expansion array. The administrator creates a RAID 5 on the expansion array, groups it with the existing RAID on the 520, and then expands the size of the original volumes using the new storage from the expansion array. Grouping RAIDs with other Grouped RAIDs Just as RAIDs can be grouped, individual groups of RAIDs can be brought together to form an even larger group. For example: A 1 TB Snap Server 520 is running out of capacity. Two 1 TB SANbloc S50s are attached to the Snap Server to provide increased capacity. You can configure a RAID 5 on each of the SANbloc S50s, then group them together. The resulting RAID group of SANbloc S50s can then be grouped with the RAID on the Snap Server, allowing network users to take advantage of the full capacity of the head and expansion arrays with no loss of capacity. Deleting Grouped RAIDs Deleting the RAID Group will delete all member RAIDs, all their volumes and shares, and all their data. If one RAID becomes inaccessible for any reason, the entire RAID group will also become inaccessible. Depending on the cause, the RAID group may or may not be recoverable. For example, if a RAID group spans a host Snap Server and a SANbloc S50 or Snap Disk expansion array and one of the RAIDs goes down because of a disconnected cable, the RAID group is fully recoverable by reconnecting the cable and rebooting the system. On the other hand, if one of the RAIDs becomes corrupted and remains unrecoverable, the data in the other RAID will also be lost. Snapshot Pools are Combined When two RAIDs are grouped, the size of the resulting snapshot pool is the sum of each RAID's formerly separate snapshot pools. 46 Snap Server Administrator Guide