HP Storage Essentials V5.1 User Guide Second Edition (Linux Release) (T4283-96056, November 2006)

Provisioning Manager370
where 0 in Group:0 is the volume identifier and LDEV:0 and LDEV:1 are the LDEVs that make up
this volume.
Creating a Storage Volume
IMPORTANT: Some storage vendors require a password to access the storage system. If the same
password is not entered, an authentication error message is displayed. Refer to Options > Storage
Essentials > Discovery > Run Discovery Details Collection in HP Systems Insight Manager to
determine the user account that was used to access the storage system during discovery.
When you create a storage volume, you can set its size, volume capabilities, and storage pool.
Volumes are shipped already created on HDS and Symmetrix storage systems. When you create a
volume in the management server on these storage systems, you are defining the volume as being
allocated.
Keep in mind the following:
• Some vendor's tools for HDS might round off the volume size, so that a 6.87-GB volume appears
as 7 GB (7168 MB) in the tool. The management server displays the size of the volume without
rounding. For example, assume you want to create a 14-GB (14336 MB) LUSE volume, and
according to the storage tool, you have two 7-GB LDEVs, which are really 6.87 GB (7034.88
MB). If you look at the native tool, it would be logical to assume only two LDEVs would be used
to create the 14-GB LUSE volume. The management server would use three LDEVs because each
LDEV is really 6.87 GB.
• If you are creating a volume on an HP EVA storage system, its external SMI-S provider may
round the specified number of megabytes to the nearest whole gigabyte.
• You cannot create volumes in existing storage pools on HP MSA and EVA storage systems.
• PvLinks based on HP disk partitions are not supported. Any volumes created on such PvLink meta
devices are shown as local. If you partition a regular (non-PvLink) external disk and create
volumes based on it, then volumes are recognized as external volumes.
Keep in mind the following for HDS storage systems:
• A LUSE volume on an HDS storage system is not created until you map that volume to a target
array port. In the management server, the create volume and LUN creation tasks are two
different operations. So if you want to create a LUSE volume and perform LUN creation on the
HDS box, it is a two-step process. First, use the management server to create LUSE volumes. The
management server puts volumes in the repository as grouped LDEVs. Then, create a LUN and
map a volume to a target port, by creating a host security group. See the topic, ”Creating Host
Security Groups” on page 380 and ”Rules for Creating Host Security Groups” on page 374.
• HDS ships some of its storage systems with volumes already created. When the software first
discovers an HDS storage system, it detects the volumes created by HDS. When you use the
software's “create a volume” feature, you are assigning the already created volume. See the
topic, ”About Provisioning on HDS Storage Systems” on page 389 for more information.
• LUSE made up of volumes from different RAID levels are not supported. You cannot use this
product to provision this type of LUSE. Existing LUSE of this type maybe incorrectly reported.