Continentalclusters Version A.05.01 Release Notes, December 2005 (T2346-90007)

Continentalclusters Version A.05.01 Release Notes
Known Problems and Workarounds
Chapter 118
Persistent “cmomd” Processes
What is the problem?
If the node where the monitor process (cmclsentryd) is running goes
down and then comes back up (as in a power failure), the cmomd process
will remain on one or more nodes in the cluster that is being monitored.
In these circumstances, the cmomd process will continue on the system
until terminated by a user. This can become a significant problem if a
monitoring node is powered off and on several times, leaving several
cmomd processes on the monitored cluster, using system process table
space as well as other system resources.
What is the workaround?
After a failure of the monitoring node, kill the unused cmomd processes.
Provider File Renaming
What is the problem?
If the provider file, which is named
/opt/cmom/providers/cmprovider.omp by default, is copied to a
backup file by adding a prefix to the name (for example,
“bk_cmprovider.omp”), then Serviceguard will not be able to tell which
file is the correct one.
What is the workaround?
Do not rename the provider file to a different name by adding a prefix. As
an alternative, store copies or alternate versions of the file in a different
directory.
Applications hang when all PV links are down
What is the problem?
When all PV links to a disk array used by a primary or recovery package
are down, the package applications accessing that array will hang
indefinitely. The applications will not detect an error and cannot be
killed. Even running cmhaltpkg will not stop the application.
What is the workaround?
The default behavior of LVM is to retry access forever following a failure.
There are a number of ways to recover from this application hang
problem: