26 Implementing the IBM Storwize V5000 Gen2 with IBM Spectrum Virtualize V8.1
Image mode volumes are special volumes that have a direct relationship with one MDisk.
They are used to migrate existing data into and out of the clustered system to or from
external FC SAN-attached storage.
When the image mode volume is created, a direct mapping is made between extents that
are on the MDisk and the extents that are on the volume. The logical block address (LBA)
x on the MDisk is the same as the LBA x on the volume, which ensures that the data on
the MDisk is preserved as it is brought into the clustered system, as shown in Figure 1-12.
Figure 1-12 Image mode volume
Certain virtualization functions are not available for image mode volumes, so it is often useful
to migrate the volume into a new storage pool. After it is migrated, the MDisk becomes a
managed MDisk.
If you want to migrate data from an existing storage subsystem, use the storage migration
wizard, which guides you through the process.
For more information, see Chapter 7, “Storage migration” on page 349.
If you add an MDisk that contains data to a storage pool, any data on the MDisk is lost. If you
are presenting externally virtualized LUNs that contain data to an IBM Storwize V5000 Gen2,
import them as image mode volumes to ensure data integrity or use the migration wizard.
1.6.10 iSCSI
iSCSI is an alternative method of attaching hosts to the IBM Storwize V5000 Gen2. The
iSCSI function is a software function that is provided by the IBM Storwize V5000 Gen2 code,
not hardware. In the simplest terms, iSCSI allows the transport of SCSI commands and data
over an Internet Protocol network that is based on IP routers and Ethernet switches.
To Next Page
Loading...
Need help?
General