You can map a to a or . When you map the first volume to a host or host group, you automatically create a storage partition. Any mappings that you create after the first mapping do not create new storage partitions. These examples show how volume mappings work.
Example 1 – You map volume 1 to a host named Fred, which creates the first map for volume 1. This mapping creates a storage partition that contains host Fred and volume 1. Then you map volume 2 to host Fred. Mapping volume 2 to host Fred does not create a new partition. The partition contains host Fred with mappings to volume 1 and volume 2.
Example 2 – You map volume 3 to host group Barney, which creates the first map for volume 3. Host group Barney contains host Bar1 and host Bar2. Mapping volume 3 to host group Barney creates a new partition. The partition contains host Bar1, host Bar2, and volume 3. Host Bar1 and host Bar2 can access volume 3 with the same . (The LUN is a value that identifies volume 3.) At a different time, you map volume 4 to host group Barney. Mapping volume 4 to host group Barney does not create a new partition. Now the partition contains host group Barney (host Bar1 and host Bar2), volume 3, and volume 4.
Example 3 – You map volume 5 to host Bar1, which is in host group Barney. When you map to a single host in a host group, you do not map to the entire host group. By mapping volume 5 to only host Bar1, you create a new storage partition. The new storage partition contains host Bar1 and volume 5. Bar2 does not have access to volume 5.
Attention:
Possible loss of data access – In some cases, the host operating system does not support mapping a base volume and the associated snapshot volume to the same host, host group, or node in a cluster. Map a snapshot volume to a single separate host instead.When you map a volume to a host, make sure you map to the host that you want to control data to the volume. If you give a volume access to an incorrect host, unexpected results can occur. For example, if you create a volume for email data, but give the email volume access to a web service host, the volume will be filled with web service data instead of email data.