HP XP External Storage Software - Manual (Page 17)

2 About External Storage
Operations
This chapter explains the functions and the applications of External Storage.
This user’s guide uses the following terms:
• An original storage system is called the local storage system.
• A connected storage system is called the external storage system (other user’s guides call this
the external device).
• The volume managed in the local storage system is called the internal volume.
• The volume in the external storage system is called the external volume.
Connecting External Storage System
External Storage enables you to use HP storage systems, original equipment manufacturer (OEM) storage
systems, and other vendors’ storage systems (such as IBM or EMC) as connectable external storage
systems. Hosts will recognize these volumes as internal volumes of the storage system.
External volume mapping is required for manipulating external volumes from storage system.
Mapping means assigning the management numbers to the external volumes. This management
numbers are required for the manipulating external volumes from storage system. By assigning the
management numbers to the external volumes, the system administrator will be able to manipulate
not only internal volumes of storage system but also external volumes using HP StorageWorks
XP Remote Web Console. The management numbers consist of external volume group number ­
sequential number (Example: E2-1, E50-3). For details on the external volume group number, see
“ Registering a Volume to an External Volume Group (ExG) ” on page 21.
Figure 3 on page 18 shows the idea of connection between a storage system and an external storage
system which are connected by the External Storage function. In the Figure 3 on page 18, the external
storage system is connected to the external port of the storage system via a switch using the Fibre
Channel interface. The external port is a kind of port attribute, which is used for External Storage. In the
Figure 3 on page 18, the external volumes are mapped as storage system volumes.
Note: Make sure that you do not access the external volume, which has been mapped as a storage
system volume, from the host that is connected to the external storage system. Also make sure that you do
not access the mapped external volume using the function (for example, copy function) of the external
storage system. Once you have mapped an external volume as a storage system volume, you have to
access the mapped external volume only from the storage system side.
Note: From the host, you can access the external storage system volumes that have not been mapped as
the storage system volumes. There is no restriction.
XP24000 External Storage Software User’s Guide 17