• Oracle Backup/Recovery
• Database Security
• Advanced Utilities and Scripts

Oracle has always been designed to run on servers with multiple physical disks, and has software mirroring built into it to protect against hardware failure. All critical files can be mirror on separate devices, so that a loss of a disk (or RAID group) may not even result in an outage, much less loss of data. Some dos and don'ts:

• Do
1. Run your database in ARCHIVELOG mode - Every tranaction is sucessfully written to the redo log before it is commited. In ARCHIVELOG mode, all redo logs are copied to 1 or more locations and verified when they are full. If you are running in ARCHIVELOG mode, you can restore individual files and apply in your database to reover all of your data. It is even possible to recover all of the data in a datafile using archive logs (if you have them all since the file was created) without any backup of the datafile at all. In contrast, if you are running in NOARCHIVELOG mode, your only restore operation is to restore the entire database from a backup and lose any transactions since the backup.
2. Protect your archive logs. Use the LOG_ARCHIVE_DUPLEX_DEST LOG_ARCHIVE_DEST_x parameters to write them to multiple destinations. ARCHIVE LOGS ARE YOUR MOST IMPORTANT BACKUPS. IF YOU ARE MISSING ONE, YOUR DATABASE RECOVERY IS STOPPED COLD. YOU CANNOT RECOVER ANYTHING PAST THE MISSING ARCHIVE LOG. In contrast, if you have your archive logs, you can restore all of your data if you have backups of your datafiles, and sometimes you can recover everything even if you don't have backups of your datafiles.
3. Keep your archive logs on different disks than any datafiles. If you have your archive logs and datafile on the same disk and lose that disk, you will lose data, as the archive logs you need to recover the datafile are also lost.
4. Get the largest disks you can for archive logs and dedicate the disks to them. Disks are cheap. Keep the archive logs as long as feasable. Remember, if your last good backup was 6 months ago, and you have a year's archive logs, you can still recover all your data.
5. Mirror your redo logs, control files, and archive logs using Oracle. Oracle provides software mirroring in addition to any RAID your hardware may have.
6. Create separate hardware RAID group for each drive letter/mount point. For simplicity and performance, use RAID1 or RAID 1/0.
• Don't
1. Use the starter database (or the GUI database assistant). Theses databases have all of their datafiles, redo logs, and archivelogs on the same drive as Oracle software, and do not take advantage of any of Oracle's built-in redundancy.
2. Create 1 big RAID5 group in server and partition it. - This common pratice gives the appearance or redundancy but provides none. If you lose the RAID group (I've seen it happen many times) in this configuration, you will lose all datafiles, archive logs, and redo logs.
3. Rely on 3rd party "open file managers" to backup an Oracle database while it is open. Use only backup methods approved by Oracle (BEGIN/END BACKUP commands and RMAN) to backup open databases. If in doubt, contact Oracle support.