Re: When to recycle logical log back up tapes

On Fri, 13 Jun 1997, Susana Cumplido-Riel wrote: } Hi, } We have Informix OnLine 7.22 running on Windows NT 4.0. We are making } daily full system backups , our database is small , about 10000 records } in the main tables ( although using Byte blobs and Text blobs). We are } also continously backing up the logical logs. } Whenever my full system data backup finishes successfully, the next } logical log to be backed up is appended to the end of the logical log } tape ( no matter if before starting my full system data backup I stop } the continous logical log backup and I restart it whenever the data } backup has finished). That means that there is a moment when the logical } log backup tape gets full, and the engine asks me to insert another tape } in the corresponding drive. } My question is : When do I know I can recycle one of the logical log } tapes. Wouldn't it make more sense that whenever a full system data } backup is finished successfully the Informix engine would know how to } rewind the corresponding logical log tape and start overwriting the old } logical logs? Or at least give you that option? What do I need logical } logs previous to my last full system data backup for? If your last full system backup should fail in recovery, you might need to go back one or more generations of fullbackups and then should require some of those backed up logical logs. Also, it is possible to trace activites by reviewing logical logs. See onlog utility. It sounds as though you have a never-eding succession of logical logs backups tapes. This can be a problem if an early volume is unreadable. Hope this helps. -- Con Woodall Colorado St. U.; Veterinary Teach. Hosp.; Ft. Collins CO 80523, USofA; 970-491-1244 FAX 970-491-4100 cwoodall@vth1.vth.colostate.edu "There is no 'maybe' in Boolean algebra." -- } } For the backup procedure we are using the user interface provided by } Informix 7.22 that indirectly uses ONBAR ( instead of ontape). } } Thanks. } } Susana. }