Can I use shared LUNs
between two nodes, so that one writes a file to the shared LUN at a time and the other maybe reads a different file from the same shared LUN periodically for SQLLDR? Currently we use NFS
to achieve the SQLLDR loads from a mountpoint. But, NFS is so slow that it is prompting us to use shared LUNS, and we don't know if this is a practical solution.
Do you have a handle as to why the NFS performance is as slow as it is? If you have not done so already, double check your file serving configuration including NFS setup for the shared data to pinpoint where the performance bottleneck exists. Look at your servers, network as well as file serving software setup.
Generally speaking the only ways that a LUN can be shared between two or more nodes is by using some form of file and data sharing, typically NFS. Some other techniques for sharing data including clustering software that supports and manages data concurrency and consistency across nodes. Some operating systems have support for limited shared read and exclusive write via special mount commands however these will vary and often have performance or other implications.
This was first published in February 2007