Compaq Infortrend Manuale Utente
Fibre Operation
8-15
Figure 8 - 2 Host-LUN Mapping
Creating LUN Masks
User can configure the storage subsystem to appear as 32 LUNs per
Fibre target ID. Each LUN can be mapped with a storage unit -a
partition or the entire logical drive. The configuration of logical
units depends on host applications and how many drives and drive
channels have been employed in the storage system.
Fibre target ID. Each LUN can be mapped with a storage unit -a
partition or the entire logical drive. The configuration of logical
units depends on host applications and how many drives and drive
channels have been employed in the storage system.
The diagram below shows the idea of the virtual connection and the
physical connection from host computers to drives. There can be
many host computers connected across a storage network and a
system administrator may want to make each storage unit available
for certain host systems while forbidden for some others.
physical connection from host computers to drives. There can be
many host computers connected across a storage network and a
system administrator may want to make each storage unit available
for certain host systems while forbidden for some others.
Figure 8 - 3 LUN Mask
The access control can also be implemented by filter drivers.
However, comparing to the control by software, access control based
on controller LUN mapping can avoid overheads on server and the
additional I/O latency.
However, comparing to the control by software, access control based
on controller LUN mapping can avoid overheads on server and the
additional I/O latency.
The LUN map combines Host ID (in the Fibre case, a 64-bit "port
name;" in the SCSI case, the initiator ID) with the list of attributes of
a LUN map that originally only consisted of the channel, target ID,
and the LUN number.
name;" in the SCSI case, the initiator ID) with the list of attributes of
a LUN map that originally only consisted of the channel, target ID,
and the LUN number.