Owner's Manual

46 iSCSI Cluster Setup for EqualLogic Storage Systems
An EqualLogic PS-series storage group can be segregated into multiple tiers
or pools. Tiered storage provides administrators with greater control over how
disk resources are allocated. At any one time, a member can be assigned to
only one pool. It is easy to assign a member to a pool and to move a member
between pools with no impact to data availability. Pools can be organized
according to different criteria, such as disk types or speeds, RAID levels, and
application types.
In Figure 6-2, pools are organized by member RAID levels:
• One pool with the name RAID-10 consists of RAID 10 members.
• One pool with the name RAID-5 consists of RAID 5 members.
Creating Volumes
Before data can be stored, the physical disks of the EqualLogic storage array
must be configured into usable components, known as volumes. A volume
represents a portion of the storage pool, with a specific size, access controls,
and other attributes. A volume can be spread across multiple disks and group
members. The volume is seen on the network as an iSCSI target. Volumes are
assigned to a pool and can be easily moved between pools, with no impact to
data availability. In addition, based on the overall workload of the storage
hardware resources within the pool, automatic data placement and automatic
load balancing occurs within a pool.
Table 6-1 shows a sample volume configuration.
Table 6-1. Volumes for Oracle RAC Configuration
Volume Minimum
Size
RAID Number of
Partitions
Used For Operating System
Mapping
First Area
Volume
1024 MB 10 Three of 300
MB each
Voting Disk,
Oracle Cluster
Registry (OCR),
and SPFILE for
ASM instance
Three block
devices, each for
Voting Disk,
OCR, and
SPFILE
Second Area
Volume(s)
Larger than
the size
of
your
database
10 One Data ASM disk group
DATABASEDG