HP-UX Virtual Partitions Administrator's Guide (includes A.03.05 and A.04.05)

I/O: Allocation Notes
When planning or performing I/O allocation, note the following:
• An LBA can be assigned to at most one virtual partition at any given time. When you are
planning your I/O to virtual partition assignments, note that only one virtual partition may
own any hardware at or below the LBA (Local Bus Adapter) level. In other words, hardware
at or below the LBA level must be in the same virtual partition.
Example Looking at the ioscan output of a rp7400/N4000, the two internal disk slots
use the same LBA:
0/0 ba Local PCI Bus Adapter (782)
0/0/2/0 ext_bus SCSI C875 Ultra Wide Single-Ended
0/0/2/1 ext_bus SCSI C875 Ultra Wide Single-Ended
Therefore, you cannot assign one of the internal disks to partition vpar1 and the other
internal disk to partition vpar2; these disks must reside in the same partition.
• Syntax Notes When specifying only the SBA on the command-line, the vPars commands
will assume the change applies to all LBAs under the specified SBA.
The exception are boot disks; boot disks are specified using the full hardware path.
NOTE: When assigning I/O, if you specify a path below the LBA level (for example,
cell/sba/lba/.../device, vPars automatically assign the LBA to the virtual partition.
For example, if you specify -a io:0/0/0/2/0.6.0 where 0/0/0 is the cell/sba/lba, the
lba of 0/0/0 is assigned to the virtual partition. Further, this LBA assignment implies that all
devices using 0/0/0 are assigned to the virtual partition.
The assignment rules of LBAs remain applicable: the LBA can only be owned by one virtual
partition. For example, once the LBA at 0/0/0 is assigned to one virtual partition, it cannot
be simultaneously assigned to any other virtual partition. Thus, if the device at
0/0/0/2/0.6.0 is assigned to a virtual partition, the LBA at 0/0/0 is assigned to that virtual
partition, so the device at 0/0/0/2/0.6.0 cannot be assigned to a different virtual partition.
LBA Example
The vparcreate command on a non-nPartitionable system looks like:
#vparcreate -p vpar1 -a cpu::1 -a cpu:::1 -a mem::1024 -a io:0.0 -a
io:0.0.2.0.6.0:BOOT
where the I/O assignment is specified using the LBA level (-a io:0.0) and the boot disk
is specified using the full hardware path (-a io:0.0.2.0.6.0).
For an nPartitionable system, the vparcreate command would look like:
# vparcreate -p vpar1 -a cpu::1 -a cpu:::1 -a mem::1024 -a io:0.0.0 \
-a io:0.0.0.2.0.6.0:BOOT
where the I/O assignment is specified using the LBA level (-a io:0.0.0.) and the boot
disk is specified using the full hardware path (-a io:0.0.0.2.0.6.0).
For information on using the LBA level on nPartitionable systems, also see “Planning,
Installing, and Using vPars with an nPartitionable Server” (page 51).
• SBA/LBA versus cell/SBA/LBA When viewing hardware paths, note the following:
1. The explicit specification of an LBA on a non-nPartitionable system consists of two
fields: sba/lba
2. The explicit specification of an LBA on an nPartitionable system consists of three fields:
cell/sba/lba
3. With A.04.xx, all LBAs under a SBA are implied when explicitly specifying a SBA
without specifying any LBA. Therefore, the path specified on a command line can have
I/O: Allocation Notes 213