I have been reading PAF5-USERS archives regarding backups, but I still have questions. When I backup to a CD-RW how often can that disk be used? My impression is that my 3347 name data base is rewritten on a new section of the disk. I learned from this list that before using a floppy, either brand new or used, I should do a scan to see if it is OK. Can a CD-RW be scanned? Does there seem to be a good reason to prefer one over the other for backups? I should add that I send my whole database to my son's computer ever so often, but not after each addition. Also from time to time I store a floppy with my daughters who live in other towns. LaVerne, Researching BACHMANN, BOEHMKE, HEMMANN, HEINEMANN, LANDL, LINHARDT, OTTO, PIETSCHMANN, ROEHL, SEHLER, TELLE, ZACHARIAE, ZEITLER

Hi LaVerne. The topic of backups is not trivial and there have been long discussions of the ins and outs of this vital topic. If I read between the lines in your message, it sounds like you backup your file each time with a different file name so that it is written on a new section of the disk. The most effective system is to append the current date to the data base name each time you backup so that you have a chronological progression of your changes. If you do not change the name, then each time you backup, the file (for all practical purposes) overwrites the previous copy. In many cases it doesn't actually overwrite the physical space on the disk. It marks the space used by the old copy as "available for use" in the directory, and creates a new entry in the directory that points to the space where the new copy is physically located. This file space management methodology is common for any type of re-writable storage whether it is your hard drive, a floppy diskette, or a CD-RW. Imagine a CD-RW disk that contains a copy of your 3347 name data base called LaVerne. The physical space that your file occupies may or may not be surrounded by other files. Suppose you add 20 more names with appropriate sources and notes which makes the file somewhat larger. If you backup the new data base with the same name of LaVerne, it will no longer fit in the space it has allocated on the CD. So your computer's file management system goes through a complicated routine to determine how to squeeze the new file into the available unused space on the disk. In some cases it may find an open slot big enough for the new file, in which case it will use that and flag the old space as available space for some other file. If it cannot find a contiguous amount of space for the whole file, it will break it up into pieces and spread it out over several slots and link them all together in the directory. These disparate pieces of a file are called "extents." If a file is broken into pieces, it takes longer for the computer to read it (because it has to chase all over the place to find what it is looking for), and it is more vulnerable to corruption (if one extent is clobbered, the whole file is lost). This whole problem is what has led to the need for "defragmentation" of hard drives in order to improve your computer's performance. In any case, you should always assign a new name (by adding the date) to your backups so that your system is not "over writing" the old version. I hope this helps. Richard Rands At 11:42 AM 3/9/2005 -0800, LaVerne T. Boehmke wrote: >I have been reading PAF5-USERS archives regarding backups, but I still >have questions. > >When I backup to a CD-RW how often can that disk be used? My impression is >that my 3347 name data base is rewritten on a new section of the disk. > >I learned from this list that before using a floppy, either brand new or >used, I should do a scan to see if it is OK. Can a CD-RW be scanned? > >Does there seem to be a good reason to prefer one over the other for backups? > >I should add that I send my whole database to my son's computer ever so >often, but not after each addition. Also from time to time I store a >floppy with my daughters who live in other towns. > > >LaVerne, > >Researching BACHMANN, BOEHMKE, HEMMANN, HEINEMANN, LANDL, LINHARDT, OTTO, >PIETSCHMANN, ROEHL, SEHLER, TELLE, ZACHARIAE, ZEITLER > > >==== PAF-5-USERS Mailing List ==== >Having trouble with the software? Check PAF 5.x Information >http://www.ausbdm.org/p5uinfo.php