Installing and Managing HP-UX Virtual Partitions (includes A.04.02)

CPU, Memory, and IO Resources (A.03.xx)
IO: Concepts
Chapter 7
198
IO: Concepts
Acronyms
LBA Local Bus Adapter
SBA System Bus Adapter
System, Cells, SBA, LBA, Devices and Relationships
On a server, an IO device communicates to the system through the LBA and SBA. The path looks like
Figure 7-1 System to IO Device Relationship
This corresponds to the ioscan hardware path output for an IO device of sba/lba/ ... /device.
A LBA actually owns all the devices attached to it. In the example below, all the IO devices attached to LBA 0
are owned by LBA 0, and the hardware paths of those IO devices begin with 0/0 (sba/lba). (Cells are discussed
later and would change the hardware path to cell_ID/sba/lba.)
Figure 7-2 LBA owns Multiple IO Devices
It is at the LBA level where vPars assigns IO. 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 IO devices attached to
LBA 0 are assigned to vparN.
Figure 7-3 vPars allocates IO at the LBA Level
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 “IO: Allocation Notes” on page 202. 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.