Dell PowerVault MD3820f - Manual (Page 163)

5. In the Map to host drop-down, specify how you want to map the host for each snapshot virtual disk
created for a selected member virtual disk.
This map attribute is applied to every member virtual disk you select in the consistency group. For
more information on the map attributes, see the online help topics.
The following guidelines apply:
– Each host has its own logical unit number (LUN) address space and will let the same LUN be used
by different host groups or hosts to access snapshot virtual disks in a storage array.
– You can define one mapping for each snapshot virtual disk in the storage array.
– Mappings are shared between RAID controller modules in the storage array.
– The same LUN cannot be used twice by a host group or a host to access a snapshot virtual disk.
You must use a unique LUN.
– An access virtual disk mapping is not required for out-of-band storage arrays.
6. Select how to grant host access to each selected member virtual disk’s snapshot virtual disk. Do one
of the following:
– Select Read/Write to provide the host application with WRITE access to a copy of the data
contained in the snapshot image. A Read-Write snapshot virtual disk requires an associated
repository.
– Select Read Only to provide a host application with READ access to a copy of the data contained
in the snapshot image, but without the ability to modify the snapshot image. A Read-Only
snapshot virtual disk does not have an associated repository.
7. Select each member virtual disk in the consistency group for which you want to create a snapshot
virtual disk.
You can click Select all to create a snapshot virtual disk for each member virtual disk displayed in the
select members table.
8. If you selected Read-Only host access in step 6, you can skip this step and go to step 9.
NOTE: Repositories are not required for Read-Only snapshot virtual disks.
9. Select how you want to create the snapshot virtual disk repositories for each member in the
consistency group. Do one of the following:
– Select Automatic and click Finish to create each snapshot virtual disk repository with the default
capacity settings. This option is the recommended one.
– Select Manual and click Next to define the properties for each snapshot virtual disk repository;
then click Finish to continue with the snapshot virtual disk creation process. You can click Edit
individual repository candidates to manually edit a repository candidate for each member virtual
disk.
Use this option if you want to specify all of the customizable settings for the snapshot virtual disk
repository. The Manual method is considered advanced and only those who understand physical disk
consistency and optimal physical disk configurations should use this method.
See the online help topics for more information on how to set the repository parameters.
The snapshot virtual disk and its properties for the associated consistency group are displayed in the
navigation tree.
Creating A Consistency Group Snapshot Virtual Disk Repository (Manually)
During the creation of a consistency group snapshot virtual disk that is designated as read-write, the
system requires a snapshot virtual disk repository for each member of the consistency group to provide
the host application with WRITE access to a copy of the data contained in the snapshot image. You can
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