HP-UX Virtual Partitions Administrator's Guide (includes A.05.02)

CPU, Memory, and I/O Resources (A.05.xx)
I/O: Allocation Notes
Chapter 6
191
I/O: Allocation Notes
When planning or performing I/O allocation, note the following:
• Mass Storage Stack Formats
The agile view of mass storage introduced in HP-UX 11i v3 (11.31) is supported with vPars. However, the
lunpath hardware path format and lun hardware path format are not supported for use on the vPars
command line, and are not printed by any vPars commands. You must continue to use the legacy
hardware path format that existed in previous vPars releases when using the vPars commands; for
HP-UX 11i v3 (11.31), ioscan’s default output will continue to show the legacy format.
However, wherever the new formats are supported by other 11.31 HP-UX commands and tools, you can
use these new formats within the virtual partitions running 11.31. For information on using the new
mass storage stack formats, multipathing, and agile addressing, see the white paper The Next Generation
Mass Storage Stack and the manual HP-UX System Administrator's Guide: Overview.
When using HP-UX commands in the agile view to affect boot paths, such as with the setboot command,
vPars requires a corresponding legacy hardware path to exist. When planning your system configuration
you should be aware that there will be no legacy hardware paths in the following cases, due to limitations
in the minor number format of legacy device special files:
— you have more than 255 I/O busses
— you have more than 32,768 LUNs. Note that for the first release of 11.31, only up to 16,384 LUNs are
supported and for 11.23, only up to 8192 LUNs are supported.
• 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 legacy hardware path.