Re: Best backup scheme of single tape drive system

Chuanlarp Satchavarodom wrote: > Dear List, > I have a question about continuous database backup for a single tape > system. I want to do continuous logical log back up, but my system has > only one tape drive. If I dedicate it to back up full log file, when I > want to do dbspace backup, I am gonna have a problem. =20 > This is what I plan to do, I will set a logical log backup to tape, > and when the schedule time for dbspace backup arrives, I will stop the > continuous log back up. Backup dbspace and perform automatic logical > log backup and turn on the continuous log again. Does this make sense? > Is there a way to better automate the whole thing with single tape = > system? You can simulate continuous log backup to disk with better safety than using ontape -c by using an ALARMPROGRAM script or executable to launch ontape -a each time a logfile is completed. A sample for doing thisusing onbar is included with the engine in $INFORMIXDIR/etc and I have both a simple script and a "C" executable to do this using ontape -a. I submitted the package to the IIUG Repository this week but it will be a few weeks before it is posted on the web. Let me know via email if you want a copy. The idea is to archive the logs to disk, rename the file so that it is not overwritten by the next log backup, then later copy the log backup files to tape with the normal system backup schedule. Since the logs are primarily needed between Informix backups you should schedule system backups between and immediately preceeding the Informix backup and the Informix backup script can then delete any log backup files older than the previous database backup on the assumption that they have been backed up already and are no longer needed. Art S. Kagel