HP-UX Virtual Partitions Release Notes (A.05.01)

Known Problems and Workarounds
evacd Daemon Monopolizes CPU During Tape Archiving
Chapter 324
evacd Daemon Monopolizes CPU During Tape Archiving
Related JAG or Patch ID Number
JAGag27792
Applicable on
vPars A.05.01
Description
The evacd daemon can monopolize CPU resources on a small virtual
partition configured with float memory. On such a system with a workload
that exhausts the file cache, the workload may run more slowly than
expected. A backup to tape such as make_tape_recovery is one such
workload.
This situation does not occur on virtual partitions configured with only base
memory.
Symptoms
An application that exhausts the file cache, such as a tape backup, takes
much longer to run. Processor monitor commands such as top show the
evacd program consuming over 90% of the CPU resources.
Workaround
There are several workarounds available. You can either
Reduce the tunable filecache_max from the default of 50% to 25%. If
the problem persists, reduce the tunable further.
or
Using vparmodify, remove the float memory from the virtual partition
before starting the application that exhausts the file cache. The float
memory can be added back after the application completes.
or
Install the patches PHKL_35899 and PHKL_35900.