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

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.
NOTE: When assigning I/O, if you specify a path below the LBA level (for example, cell/
sba/lba/.../device, vPars automatically assigns 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 0/0/0/3/0.6.0 cannot be assigned to a different virtual partition.
LBA Example
The vparcreate command on a non-nPartitionable system looks like:
184 CPU, Memory, and I/O Resources (A.05.xx)