NFS and Oracle GoldenGate
Oracle GoldenGate Best Practice: NFS Mount for use with Oracle GoldenGate
GoldenGate - Version: 10 or later
The purpose of this document is to setup the file system mount options to be used when using GoldenGate to run with NFS mounted file system.
Unless IO buffering is OFF, then NFS mounts should not be used when running any Oracle GoldenGate processes. The danger occurs when one process registers the end of a trail file or transaction log and moves on to the next in sequence yet after this event data in the NFS IO buffer gets flushed to disk. The net result is skipped data and this cannot be compensated for with Oracle GoldenGate parameter EOFDELAY.
When using an NFS mounted file system with Oracle GoldenGate files, the setting for file system caching or buffered IO must be disabled on both NFS client and server.
The important factor to consider when configuring Oracle GoldenGate processes to run on NFS mounted file system is to make sure that buffered IO (data and attribute caching) is always set to OFF on both NFS client and server.
Oracle GoldenGate Best Practice: NFS Mount options for use with GoldenGate
Oracle GoldenGate files includes Binaries, Checkpoint files, Parameter files, Report files and Trail Data files
| NFS Client Operating System | NFS Client Mount options for Oracle GoldenGate Files |
|---|---|
| SUN Solaris * | rw,bg,hard,nointr,rsize=32768,wsize=32768,proto=tcp,noac,forcedirectio, vers=3,suid |
| AIX (5L) * | cio,rw,bg,hard,nointr,rsize=32768,wsize=32768,proto=tcp,noac,vers=3,timeo=600 |
| HPUX 11.23 * | rw,bg,vers=3,proto=tcp,noac,forcedirectio,hard,nointr,timeo=600,rsize=32768,wsize=32768,suid |
| Linux (x86-32/x86-64/Itanium) * | rw,bg,hard,nointr,rsize=32768,wsize=32768,tcp,actimeo=0,vers=3,timeo=600 |
*Although data caching or buffered IO is set to OFF on the NFS client system, sometimes for other specialized file system such as Veritas File System (VxFS) or with NAS device/server that supports additonal caching feature such as FlexCache system on NetApp this will not take into effect unless you explicitly disable this function on the server side. For VxFS, this can be done by setting MINCACHE to DIRECT or UNBUFFERED and for the NetApp the FlexCache system must not be used at all with Oracle GoldenGate processes.
| NFS Server Operating System | Additional Mount option on NFS server local disk ** |
|---|---|
| SUN Solaris | forecedirectio |
| AIX 5L | cio |
| HPUX 11.23 | no_fs_async |
| Linux (x86-32/x86-64/Itanium) | sync |
| NetApp (Data OnTap) | Optional FlexCache system must be disabled |
** This option is in addition to the regular local file system mount options used to mount the local disk to be used by the NFS client system where Oracle GoldenGate files will be used. This setting will foreced the IO behavior setting on the file system to be synchronous "sync". Asynchronous IO behavior setting on the file system is not recommended for Oracle GoldenGate files and must be turned off at all times.
(Referenced from metalink)
