HP-UX 11i June 2001 Release Notes

Process, Threads, Memory, and Kernel Parameters
Asynchronous Disk Pseudo Driver (async) Compatibility (new at 11i original release)
Chapter 8172
Asynchronous Disk Pseudo Driver (async)
Compatibility (new at 11i original release)
The async driver is used mostly by databases for doing asynchronous I/O
to the disk.
Applications that use the async driver must be owned by the superuser,
or by a user who is a member of a group for which the privileges include
MLOCK.
To check a group’s privilege capabilities, issue this command:
/usr/bin/getprivgrp group_name
If the output of getprivgrp does not show that the group has the MLOCK
privilege, set the group’s privilege by issuing this command as root:
/usr/bin/setprivgrp <group_name> MLOCK
Impact
If the application accessing async driver is not owned by superuser or by
a user who is a member of a group that has MLOCK privilege,
ASYNC_CONFIG and ASYNC_ADDSEG ioctl() will fail and errno will be
set to EPERM.
Compatibility
An application running on HP-UX 11.0 with patch PHKL_22126
installed will operate correctly when upgraded to 11i.
If the application using async driver was operating on a 11.0 system
without PHKL_22126, then the group associated with that application
must be modified to include the MLOCK privilege when migrating to
HP-UX 11i.