Managing Virtual Device Luns; Default Lun Numbering - HP StorageWorks 12000 User Manual

From Command View VLS:
1. On the System tab, select Chassis from the navigation screen to open the Chassis status screen.
2. Select Reclaim Space in the task bar.
The VLS system initiates space reclamation and the Notifications screen displays a notification
of the scheduled reclamation.

Managing Virtual Device LUNs

The following information varies in some places from VLS firmware version 2.x and version 3.x and
is noted where this occurs.
The VLS has a LUN masking, a LUN mapping, and a port mapping feature that allows you to restrict
host access to the LUNs (virtual libraries and tape drives) configured on the VLS and assign each
virtual device to a specific Fibre Channel host port. These features allow you to allocate the virtual
devices to individual hosts and distribute the virtual tape drives across the Fibre Channel host ports
to achieve maximum bandwidth. See
VLS firmware version 3.x: You can set a global default so that either the VLS allows all hosts connected
to the VLS through the SAN to access all virtual devices configured on the VLS, or the VLS prevents
all hosts from viewing any virtual devices until they are explicitly mapped to the host. Each time you
add a new host to the VLS, it takes the global default you have set. The VLS firmware also manages
the LUN numbering so that the virtual device LUN assignments always meet operating system
requirements and restrictions. See
LUN Requirements and
Mapping (v3.x)" on page 123 for details of these features.
VLS firmware version 2.x: By default, the VLS allows all hosts connected to the VLS through the SAN
to access all virtual devices configured on the VLS. Also, the VLS firmware manages the LUN mapping
so that the virtual device LUN assignments always meet operating system requirements and restrictions.
See "Default LUN
Restrictions" on page 121. Optionally, you can restrict host access to individual virtual devices using
the LUN masking feature then, for each LUN masked host, to use the LUN mapping feature to manually
assign LUN numbers to any virtual devices you want the host to be able to access. See
(v3.x)" on page 121 and
features.
Port mapping is required and allows you to assign each virtual device to one of the Fibre Channel
host ports or a pair of Fibre Channel host ports (if your backup solution supports this).

Default LUN Numbering

The VLS automatically assigns a logical unit number (LUN) to each virtual library and tape drive
created on the VLS in the order in which they are created by you, starting with LUN0 and increasing
incrementally by one as each new virtual library or tape drive is created on an Fibre Channel host
port (LUN1, LUN2, and so on). The first virtual device port mapped to any of the Fibre Channel host
ports is assigned the LUN number LUN0. The second virtual device port mapped to an Fibre Channel
host port is assigned the LUN number LUN1, and so on.
The default LUN numbers are changed by the VLS firmware when the VLS device emulations are
restarted if:
• A virtual device has been deleted since the last restart, creating a gap in the LUN numbering, or
• A virtual tape drive has been added to a library since the last restart and the default LUN number
it was assigned is not consecutive with the other virtual tape drives in the same library.
120 Configuration
"Managing high
"Default LUN
Restrictions" on page 121. See
Numbering" on page 120 and
"LUN Mapping (v3.x)" on page 123 for reasons you may want to use these
availability" on page 141 for more information.
Numbering" on page 120 and
"LUN Masking (v3.x)" on page 121 and
"Operating System LUN Requirements and
"Operating System
"LUN
"LUN Masking