The Lenovo Storage V7000 initialization
includes a process called discovery.
The discovery process systematically
recognizes all visible ports
on the SAN for devices that identify themselves as storage systems and
the number of logical units (LUs) that they export. The LUs can contain
new storage or a new path for previously discovered storage. The set
of LUs forms the Lenovo Storage V7000 managed
disk (MDisk) view.
The discovery process runs
when ports are added
to or deleted from the SAN and when certain error conditions occur.
You can also manually run the discovery process using the
detectmdisk command-line
interface (CLI) command or the
Discover MDisks function
from the
management GUI.
The
detectmdisk command and the
Discover
MDisks function have the
clustered system rescan
the
Fibre Channel network. The rescan
discovers any new MDisks that might have been added to the system
and rebalances MDisk access across the available storage-system device
ports.
Note: Some storage systems do
not automatically export LUs to the Lenovo Storage V7000.
Guidelines for exporting LUs
Ensure that
you are familiar with the following guidelines for exporting LUs to
the Lenovo Storage V7000 system:
- When you define the Lenovo Storage V7000 as
a host object to the storage systems,
you must include all ports on all nodes and candidate
nodes.
- When you first create an LU, you must wait until
it is
initialized before you export it to the Lenovo Storage V7000.
Attention: Failure to wait for the LUs to initialize can result
in excessive discovery times and an unstable view of the SAN.
- Do not present new LUs to the Lenovo Storage V7000 until
the array initialization and format is complete. If you add a LUN
to a storage pool before the
array initialization format is complete, the storage
pool goes offline. While the storage
pool is offline, you cannot access the volumes that are in the storage pool.
- When you export
an LU to the Lenovo Storage V7000,
the LU must be accessible through all ports on the storage system that
are visible to the Lenovo Storage V7000.
Important: The LU must be identified by the same logical
unit number (LUN) on all ports.