HP-UX Virtual Partitions Administrator Guide (includes A.05.07) (5900-1229, September 2010)

• “I/O: Concepts and Functionality” (page 180)
• “I/O: Adding or Deleting LBAs” (page 182)
• “I/O: Allocation Notes” (page 184)
I/O: Concepts and Functionality
With vPars, you allocate I/O resources at the LBA level.
LBA Local Bus Adapter
SBA System Bus Adapter
System, Cells, SBA, LBA, Devices and Relationships
On a server, an I/O device communicates to the system through the LBA and SBA. The path
looks like Figure 6-1.
Figure 6-1 System to I/O Device Relationship
Syste m
Syste m Bus
Adapte r
Local Bus
Adapte r
IO Devic e
This corresponds to the ioscan hardware path output for an I/O device of sba/lba/ ...
/device.
A LBA actually owns all the devices attached to it. In the example below, all the I/O devices
attached to LBA 0 are owned by LBA 0, and the hardware paths of those I/O devices begin with
0/0 (sba/lba). (Cells are discussed later and would change the hardware path to cell_ID/sba/lba.)
Figure 6-2 LBA Owns Multiple I/O Devices
LBA 0Syste m SBA 0
IO Device s
It is at the LBA level where vPars assigns I/O. In the example below, this means that LBA 0 can
be assigned to at most one virtual partition. If LBA 0 is assigned to vparN, it is implied that all
I/O devices attached to LBA 0 are assigned to vparN.
Figure 6-3 vPars Allocates I/O at the LBA Level
Syste m SBA 0
a LBA
assignabl e
to a vpar
0/0
LBA 0
IO Device s
A SBA has multiple LBAs attached to it; it is a hierarchical relationship. Nevertheless, assignments
in vPars remain at the LBA level, and each LBA can be assigned to a different virtual partition.
NOTE: Regarding syntax and how vPars commands interpret what is specified on the command
line, see “I/O: Allocation Notes” (page 184). Even if there are shortcuts in assigning LBAs, vPars
assigns per LBA.
In the example below, each LBA (shown in brackets) can be assigned to a different virtual partition.
180 CPU, Memory, and I/O Resources (A.05.xx)