Chapter 8. Clustering

Support for IBM iPDU Fence Device
Red Hat Enterprise Linux 5.9 adds support for the IBM iPDU fence device. For more information on the parameters of this fence device, refer to the Cluster Administration guide.
DLM Hash Table Size Tuning
The Distributed Lock Manager (DLM) now allows tuning of DLM hash table sizes from the /etc/sysconfig/cman file. The following parameters can be set in the /etc/sysconfig/cman file:
DLM_LKBTBL_SIZE=<size_of_table>
DLM_RSBTBL_SIZE=<size_of_table>
DLM_DIRTBL_SIZE=<size_of_table>
which, in turn, modifies the values in the following files respectively:
/sys/kernel/config/dlm/cluster/lkbtbl_size
/sys/kernel/config/dlm/cluster/rsbtbl_size
/sys/kernel/config/dlm/cluster/dirtbl_size