Use of Symbolic Links (UNIX)
Ingres does not support or recommend the use of symbolic links to change locations in UNIX. (This is possible with the UNIX ln command, which allows the UNIX system administrator to create symbolic links to new directories so that files are found in another directory even though the values of Ingres installation location variables remain unchanged.)
Common problems that arise from the misuse of symbolic links are as follows:
• Any files to which Ingres writes must reside on a file system that is local to the machine on which the writing process is running. This is necessary because of the operating system’s inability to guarantee network writes. If symbolic links are used, writable directories can mistakenly be mounted from remote machines. This can cause write errors and data corruption.
• Occasionally Ingres executables reside on NFS file systems that have been exported with the - nosuid option. The permissions appear normal when the ls -l command is issued, but setuid programs fails with permission errors.
• The rm command does not remove files that are symbolic links. Instead, the symbolic link itself is broken, but the original file remains. This can cause cleanup routines to fail in some circumstances.