Transferring the Lock information
If you use an NFS server function, set it so that the Lock information for NFS is succeeded.
If a transfer of the Lock information for NFS is not possible, you can get multiple Lock information for the same file. Therefore, the application that uses fcnlt(2) and lockf(3C) cannot execute the exclusive control. And it becomes the factor to cause file destruction.
But the following attention is necessary on using this function. Execute the next attention whether an application uses a lock unidentified.
On the node operation with NFS servers, do not use the NFS client function. Do not implement NFS mount.
A file system in which NFS is shared with the operation of NFS servers must be used only from the NFS client. Do not use a file directly from an application on a node on which NFS servers are operating.
When failover occurs, the following processing is performed. The access from the client is reserved until the NFS lock recovery processing is completed though the state of the resource becomes Online when the start of statd and lockd is completed.
Stopping the statd(1M) and lockd(1M) daemon
Starting the statd(1M) and lockd(1M) daemon
NFS lock recovery processing
Protocol
NFS can use TCP and UDP protocols. After using TCP for failover and failback in sequence, recovery sometimes takes longer than with UDP.
Therefore, please use the UDP protocol in PRIMECLUSTER.
