Installing and Managing HP-UX Virtual Partitions (includes A.03.03)

CPU, Memory, and IO Resources
IO: Concepts
Chapter 6
156
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 6-1 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 6-2 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 6-3 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 (vPars A.04, A.03 and earlier)” on page 160. 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.