Hopefully the obsessed photographers here will have at least a good idea about this subject as the experts on any photo list :-) : Summary: Seeking opinions re duplicate-file location and management software. Needs to work with essentially unlimited capacity and number of files and number of connected or disconnected drives. "Actually working" is highly desirable. Free would be nice but is not essential. Emphasis is on photo files. _________________ I have a large photo collection scattered across many hard drives of various capacity and vintage. There are also DVD and CD backup copies although (wisely or not) in recent years I've tended to use multiple HDDs rather than DVDs for backup. The older the files the more likely that there are numerous "lost" copies. It would be nice to be able to relate & control the number of copies of a given original file. The copies may be identical or have different compressions or in some cases reduced resolutions. Copies will almost invariably share the same basic file name and date and time but may have extended names - usually as suffixes (added on end of original name) but in some cases also as prefixes (meaning ful prefix added at start of name)(and/or even a date coded prefix added.) All copies of a file that matter will share the original EXIF information. Original date/time is preserved to the maximum extent possible**. (Some copying or editing processes* destroy EXIF informatio! n but I try to avoid this whereever possible).(* eg Photoshop has a nasty habit of playing with the EXIF).(** Some programs attempt to apply current date/time despite one's intentions and some (like eg Microsft Windows itself !!!) tend to corrupt the date/time on transfer from eg storage media. It is not uncommon for Windows itself to not be able to properly handle the time/date format of files coming from eg cameras or flash cards and to move the time 12 hours or 1 day or swap day/month or play other games. In such cases the EXIF is usually untouched and can be used to subsequently restore the correct values). (Microsoft have produced software to address this shortcoming in their own products but using it may require you to be embedded in their surrounding cotton wool). . At various stages the control of backups has been reasonably well controlled but occasionally Murphy sneaks in and ... . It is likely that there are at least two copies of every file available. In some cases there are many many more copies. (eg a wedding will have a master copy and a working copy and then subsets and versions and ...). I'd like to tidy up a vast number of files covering many GB of capacity and numerous hard drives. Possibly also various DVDs. Some but not all the drives will be live at once. Drive sizes are typically in the 300GB - 1 TB range but may be down to ?30GB?. Total originals are probably in the 100,000 - 1 million range, intended backups at least double the count, working copies probably add 50% more (only major 'events' get substantial work) and the serendipitous copying (disc upgrades etc) add some more. A total file count under 10 million would probably suffice - and it may be much lower than that. It is almost certain that no existing duplicate management system will meet my need and I'll have to write something myself. But, it would be nice to hear what people do to manage such large collections. "Doing it properly" (apart from doing it from the start) probably involves correlation of core file names, date/time Russell -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist