HP-UX 11i Version 2 Installation and Update Guide, May 2005

Known Problems and Troubleshooting
Known Install and Update Problems
Appendix B 153
System Hangs After
Issuing Large I/O (>512
KB in size) to Fibre
Channel Devices
System hangs may be experienced after issuing large I/O
(>512 KB in size) directly to physical disks accessed by a
single port Fibre Channel adapter (product number A6795A
or A5158A, claimed by the td driver).
I/O through file systems and/or logical volumes will not issue
such a large I/O. But LVM operations, for example, lvextend
and lvremove, performed on a volume group with a large
number of disks may issue large I/O for updating LVM
metadata on the physical disks. A fix will be provided at a
later date.
What To Do
A workaround is available which basically limits the
maximum I/O to a Fibre Channel device to 512 KB. But some
performance degradation may result from this workaround.
Contact HP Support to discuss the problem.
HP Does Not
Recommend
Combining Root ("/")
and Boot ("/stand")
Directories
When creating a custom file system configuration that
utilizes volume management, having the root ("/") and boot
("/stand") directories on the same partition is not
recommended. Default configurations have root and boot
directories in separate partitions when volume management
is active.
What To Do
The preferred approach is to use the default file system
configuration when installing HP-UX. If you chose to create a
custom file system configuration utilizing volume
management, make sure that root and boot directories are on
separate partitions.
Table B-1 Known Install and Update Problems (Continued)
Problem Description/Action