Performance Issues
Quick I/O File system performance is adversely affected if a cluster file system is mounted with the qio option enabled and Quick I/O is licensed, but the file system is not used for Quick I/O files. Because qio is enabled by default, if you do not intend to use a shared file system for Quick I/O, explicitly specify the noqio option when mounting.
Low Memory
Under heavy loads, software that manages heartbeat communication links may not be able to allocate kernel memory. If this occurs, a node halts to avoid any chance of network partitioning. Reduce the load on the node if this happens frequently.
A similar situation may occur if the values in the /etc/llttab and /etc/llthosts files on all cluster nodes are not correct or identical.
12 Overview