HP XP P9500 Storage - Manual (Page 19)

Thin Provisioning enhances volume performance. This is an automatic result of how THP V-VOLs
map capacity from individual THP pools. A pool is created using from one to 1024 LDEVs (pool
volumes) of physical space. Each pool volume is sectioned into 42-MB pages. Each page is
consecutively laid down on a number of RAID stripes from one pool volume. The pool’s 42-MB
pool pages are assigned on demand to any of the THP V-VOLs that are connected to that pool.
Other pages assigned over time to that THP V-VOL randomly originate from the next free page of
some other pool volume in the pool.
Setting up a Thin Provisioning environment requires a few extra steps. You still configure various
array groups to a desired RAID level and create one or more volumes (LDEVs) on each of them
(see
“Creating an LDEV” (page 51) ). Then set up a Thin Provisioning environment by creating one
or more THP pools of physical storage space that are each a collection of some of these LDEVs
(THP pool volumes). This pool structure supports creation of Thin Provisioning virtual volumes (THP
V-VOLs), where 42-MB pages of data are randomly assigned on demand.
For detailed information, see “Configuring thin provisioning ” (page 74) .
When to use Thin Provisioning
Thin Provisioning is a best fit in an open-systems environment in the following scenarios:
•
Where the aggregation of storage pool capacity usage across many volumes provides the
best opportunity for performance optimization.
•
For stable environments and large consistently growing files or volumes.
•
Where device addressing constraints are a concern.
Thin Provisioning advantages
With Thin Provisioning Without Thin Provisioning Advantages
You can logically allocate more capacity than
is physically installed. You can purchase less You must purchase physical disk capacity for
expected future use. The unused capacity adds Reduces initial costs
capacity, reducing initial costs and you can add
capacity later by expanding the pool. costs for both the storage system and software
products.
Some file systems take up little pool space. For
more details, see
“Operating system and file
system capacity” (page 79) .
When physical capacity becomes insufficient,
you can add pool capacity without service
interruption. You must stop the disk array to reconfigure it. Reduces
management costs
In addition, with Smart Tiers you can configure
pool storage consisting of multiple types of data
drives, including SSD, SAS, SATA, and external
volumes. This eliminates unnecessary costs.
P9500 product licenses are based on used
capacity rather than the total defined capacity. As the expected physical disk capacity is
purchased, the unused capacity of the storage Reduces
management labor
You do not need to use LUSE because you can
allocate volumes of up to 60 TB regardless of
physical disk capacity.
system also needs to be managed on the
storage system and on licensed P9500
products. and increases
availability of
storage volumes for
replication
Smart Tiers allows you to use storage efficiently
by automatically migrating data to the most
suitable data drive.
Effectively combines I/O patterns of many
applications and evenly spreads the I/O activity Because physical disk capacity is initially
purchased and installed to meet expected Increases the
performance
across available physical resources, preventing future needs, portions of the capacity may be efficiency of the data
drive
bottlenecks in parity group performance. unused. I/O loads may concentrate on just a
Configuring the volumes from multiple parity subset of the storage which might decrease
performance.
groups improves parity group performance. This
When to use Thin Provisioning 19