Adaptec 5325301656 - Snap Server 14000 NAS, Administrator'S Manual

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RAIDs
46 Snap Server Administrator Guide
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.