Hardware manual

7–1
7 Storage pools
About storage pools
Storage pools allocate storage space into partitions comprising one or more members.
By default, a group provides a single pool of storage. If your
group has multiple members, you can divide group
space into different pools and then assign members.
Note: Load balan
cing operates only within pools.
By default, a PS Series group provides a single pool of storage. From this pool, you
allocate space to users and
applications by creating volumes, which are seen on the network as iSCSI targets.
When you first create a group, there is one storage pool in a group, called
default. Unless you specify a different
pool, members and volumes are assigned to the default pool.
Restriction: Yo
u cannot delete the default storage pool.
However, some environments might need to segregate storage space. In
this case, you can divide PS Series group
space into multiple storage pools. Using this “SAN within a SAN” technology, administrators can easily separate
workloads, while retaining the advantages of storage consolidation.
For example, you can segregate storage space according
to application, service level, RAID type, or department.
Mission critical applications can use storage resources that ensure fast and consistent performance, while little-
used or archived data can use different resources.
To use multiple storage pools, a group must contain more
than one member. You can then assign members to
different pools. A pool can contain multiple members. Performance load balancing occurs only across the pool
members. You can create up to four pools in a group.
After you assign a member to a pool, you ca
n assign volumes to the pool. Only the resources that the pool members
provide are available to the volumes. As capacity needs change, you can move members or volumes from one pool
to another, while data remains online.
For detailed information about using storage pools,
see the Technical Report Deploying Pools and Tiered Storage
in a PS Series SAN, which you can download from the EqualLogic customer support website.
Configuring a storage pool
To plan a storage pool configuration, you must understand the capacity and RAID policy of your group members
and also the capacity, performance, and service level needs of your volumes. This enables you to select the
appropriate members for each pool and then identify the volumes to assign to the pools. Try to identify future
demands for capacity and performance when planning the storage pool configuration.
Identify the following:
• Capacity and performance of each member
. Consider the foll
owing factors:
– Disk type, either Serial Attached SCSI (SAS) or Serial Advan
ced Technology Attachment (SATA)
–Disk size