Paul Karman

An Rman Kiss Backup System

Kiss -> Keep It Small and Simple.

It is a noble goal to make life as easy as possible, well...not harder then necessary.

This page is going to supply you with the complete description of a small, simple, worry free, high performance rman based backup system for an equally small database. (mind you, a terrabyte is almost concidered small nowadays.)

Soo.. how do we make RMAN easy....

Simplification ONE

The first big simplification for setting up an rman backup system is to forget about the repository. Sure you will miss out some nice functionality but if you just want to have a reliable backup/recovery system then just forget about that backup repository or catalog. In doing so there is no need to create and maintain a separate database for that repository, no extra network configuration, no need for safeguarding and maintaining the integrity of the information about the backups and no need to understand and remember a whole range of obscure commands to manipulate all the data in that special database.

WOW !!

....but... don't we need some sort of history to keep track of which backups have been made and which ones can be cleaned up? Yes we do, and that why this information is by default stored in the good old controlfiles ! So remember... our metadata about the backups is stored in the CONTROLFILES. And to stay ahead of you, don't worry about losing the controlfiles either, there are simple ways to work around it even if you lose all copies.

Simplification TWO

The second significant simplification is that we are not going to worry about any plug-ins to control a tape robot or any other complex storage device. We are just going to assume that a gigabyte is in the end just as expensive on tape as it is on disk. So we are going to write our backups to disk. But these disks can be usb devices, nfs devices or just normal file systems. We do however want to make sure that the dreaded rm -rf / will not be your EOL so there is some special attention to that phenomena.

Simplifications THREE, FOUR and FIVE

Other things we are not going to use are ASM, PL-SQL and dbms_jobs. Advanced Storage Manager for the database is fine because the backup and restore procdures will be largely black boxed anyway. But storing backup sets in ASM defeats the purpose of this KISS system; a System Administrator should be comfortable with the procedures without the need for an extensive Oracle DBA training. For that same reason we are not using PL-SQL and Oracle's beautiful job scheduler because a system administrator is much more comfortable with shell scripting and cron.

These simplifications will make an rman backup system tremendously more understandable while it will in no way compromise its one and most important reasons for existence: backup and recovery. I would even dare to say it will increase safety just because a simpeler system is less prone to human error.

I will describe a working example system including scripts and commands to configure and execute backups and restores. The only thing necessary to make it work on your site is probably limitted to changing some database names and file destinations. Other then that this system will work.

This is probably also the right moment for the usual disclaimer stating that although I took great care to write everything flawlessly I can not accept any responsibility for any damage resulting from this document and the accompanying scripts. There is simply no substitute for testing.