Release Notes

12 Migrating an Oracle Database to Dell EMC SC Series Storage | CML1001
3.3.2 Protecting Oracle with snapshots and a consistency group
The SC Series storage snapshot feature can be incorporated into the existing backup/restore strategy.
Enabled through the snapshot profile, it protects an Oracle database by creating fast and space-efficient
snapshots of the storage volumes. To access or restore data from a snapshot, a view volume is created and
mounted with full access on any recovery system. A view volume shares the frozen pages with the parent
volume and only changed data consumes storage. Changes to the view volumes do not affect their parent
volumes. A view volume is treated like a regular volume in that it has its own volume attributes. A view volume
is useful for:
• Offloading the backup processing from the primary server
• Creating a thin clone of a full-size production environment for testing, support, or troubleshooting
• Allowing for fast data recovery
If multiple storage volumes are used for a single Oracle database, the consistency group feature must be
used along with the snapshots. If the entire Oracle database resides on a single volume, using a consistency
group is not required.
The consistency group feature allows storage administrators to take a database-consistent snapshot when
the BEGIN/END BACKUP database commands are invoked before and after each snapshot is taken. Make
sure that all storage volumes (LUNs) that make up the database have the same consistent snapshot profile
assigned. On the Oracle side, use ALTER DATABASE BEGIN BACKUP and END BACKUP before and
after the snapshot is taken. Otherwise, Oracle might not be able to recover from a multi-volume snapshot.
3.3.3 Achieve greater storage efficiency with storage profiles
Automatic intelligent data placement is a stable feature of SC Series storage. Administrators only need to
associate the volumes with one of the pre-defined storage profiles and SCOS handles the movement of data
accordingly. Some storage profiles become available when certain storage media types are installed in an SC
Series array. Table 1 and Table 2 summarize the available storage profiles.
Storage profiles available with write SSDs and HDDs, or with HDDs only
Name
Initial
write tier
Tier (T) and RAID levels
Progression
Recommended (All Tiers)
1
Writes: T1 RAID 10
Snapshots: RAID 5/RAID 6
To all tiers
High Priority (Tier 1)
1
Writes: T1 RAID 10
Snapshots: T1 RAID 5/RAID 6
Stay in tier 1
Medium Priority (Tier 2)
2
Writes: T2 RAID 10
Snapshots: T2 RAID 5/RAID 6
Stay in tier 2
Low Priority (Tier 3)
3
Writes: T3 RAID 10
Snapshots: T3 RAID 5/RAID 6
Stay in tier 3