White Papers

Best Practices for Oracle 11g Backup and Recovery using RMAN and Dell EqualLogic Snapshots
2
5.1 EqualLogic volume and snapshot collections
EqualLogic PS Series arrays provide the ability to create Volume Collections. Volume collections are
useful when you need to perform an operation simultaneously on multiple volumes. Once you have
created a volume collection you can create a snapshot of the entire collection in one operation. This
feature can be very useful in Oracle environments because Oracle database files are typically spread
across multiple volumes. When you create a snapshot of a volume collection you maintain
consistency across all volumes.
In our test configuration, the Oracle database was spread across six volumes on the array (ORADB1 to
ORADB6). The redo log data was spread across two volumes (ORALOG1 and ORALOG2). (Refer to
Table 3 in Section 3.1.) We created a volume collection group consisting of all the data file volumes
and redo log volumes. The volume collection is shown Figure 6.
Figure 6 – Data file volume collection
A single snapshot creation operation on the volume collection shown in Figure 6 will create snapshots
of all individual volumes that are part of that collection. The result of that operation is shown in Figure
7.
Figure 7 – Snapshot Collection