Owner's Manual

48 Setting Up an iSCSI Cluster
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 RAID10 members.
• One pool with the name RAID 5 consists of RAID5 members.
Creating Volumes
Before data can be stored, the physical disks of the EqualLogic PS5000XV
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.