Table 1-5 Assignment Mode of PCI Device
Scheduling
Mode
Features
Recommended
System
Dedicated
Mode
A single PCI device is assigned to a single LPAR
(guest OS). The guest OS uses the assigned PCI
device exclusively, so that its I/O performance
is stable.
When 2 ports are implemented in a PCI device,
each port cannot be assigned to a separate
LPAR.
System required high
processing
performance
System required
critical time period and
high processing in
performance
Shared Mode
A single PCI device is assigned to multiple
LPARs (guest OSs). Each guest OS can use the
assigned PCI device at the same time without
knowing that the PCI device is shared with other
OSs.
NIC performance of an LPAR is affected by I/O
load of other LPARs.
System required cost
efficiency and
flexibility rather than
high processing
performance
System required
balanced processing
between LPARs
Exclusive
shared mode
A single PCI device is assigned to a single LPAR
(guest OS). PCI device assignment can be
changed without stopping operation of LPAR. A
single LPAR can be used, multiple LPARs cannot
be used at the same time.
USB/KVM, and remote
console
Dedicated Mode
Example of Dedicated Mode is below.
Figure 1-20 PCI Device Assignment of Dedicated Mode
1-20
LPAR manager Functions
Hitachi Compute Blade 500 Series Logical partitioning manager User's Guide