Re: Informix backup - questions

Hi, please see my comments "in-lined" below ... Regards, Martin -- Martin Fuerderer IBM Informix Development Munich, Germany Information Management owner-informix-list@iiug.org wrote on 25.05.2005 22:52:09: > Thank you so much. It works great that way. Bless you that helped me. > > Forgive my ignorance but I am a network admin not a DBA so bear with me, please > > What I am planning is to write a shell script which will make the > backup in a file ontape -s, zip the file and copy it in a hard drive > where I will keep all of the backups. > The zip file will have the date stamp as part of its name so I won't > overwrite the files. > Then the backup file will be deleted and an empty one will be created > so the next backup can be written (or can the file be overwritten > without problem ?) > > Does this sound ok ? This should work. You will have the backups as long as the hard drive where they are on are readable. If something happens to that hard drive, then you will have no backups. This is one of the reasons why usually such file backups are written to tape eventually (in a third step after the compress/gzip). A tape can be stored independently and possibly at a different location, i.e. you would still have the data on the tape if the machine got stolen or destroyed by fire, etc. > I am planning to run a 0 level backup once a week and a 1 level backup > every night. Sounds good. > Do I need to backup logical logs as well (ontape -a) besides ontape -s ? It depends. There are at least 2 situations where you need logical log restore: - If you want to recover work that is done during the day. Say you do your backup at night. The following day work is done for 8 hours and some harddisk crashes at 6pm. You then would have to restore last nights backup and have lost the days work without logs to restore. - If you want to warm restore single dbspaces. See my earlier e-mail to your other question ... As a general rule I'd recommend backing up log files as it will keep you more options in the event of a problem. Probably you will want to backup the logs as soon as they get full. If you backup the logs only when you do the dbspace archive, then they may not be of much help (because those last logs that you need most to recover recent work will not have been backed up yet and may be destroyed on disk already ...). > What about the block size ? I am keeping it 1024. Is it ok ? That should work. For optimal values you have to check how your OS writes to and reads from the target hard disk (where you put the backups originally before the zipping) ... > And what about the tape size ? I have no idea how big the file might > be. How big should be the tapesize ? Which version of IDS are you using ? Since version 9.40.UC1 you can specify a tapesize of 0 which means it will use the full tape capacity before requesting a new tape. I think this also works for files, i.e. the file will get as big as necessary. And if your file system gets full, then you have a problem anyway ... > If there is any manual for dummies on informix backup out there please > let me know. Hmm. The "IBM Informix Backup and Restore Guide" should be quite readable and understandable. Other than that I don't know. > Genti sending to informix-list