Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!apple!chuq From: chuq@Apple.COM (Chuq Von Rospach) Newsgroups: comp.sys.mac Subject: Re: Backup utility that compresses Message-ID: <37991@apple.Apple.COM> Date: 22 Jan 90 05:35:50 GMT References: <1990Jan21.221803.11834@smsc.sony.com> Distribution: na Organization: Fictional Reality: where your dreams can come true Lines: 91 dce@smsc.sony.com (David Elliott) writes: [[about weaknesses of FastBack II, and askes....]] >(It would be nice if someone with Retrospect could tell me how it >fares in the above areas.) >In article <1990Jan13.012318.28263@deimos.cis.ksu.edu> jxf@phobos.cis.ksu.edu (Jerry Frain) writes: >>Does anyone out there know of a backup utility that *compresses* data as >>it writes it to [floppy] disk? >It does a pretty good job of compression. So does Retrospect. It uses a compression algorithm very close to StuffIt. On general data, I see 45-55% reduction (for instance, my ~80 floppy set of Publish domain stuff went to about 35 floppies). Some stuff -- encrypted files and Adobe fonts -- have essentially no compression, but TIFF files can compress 85% or more depending on how complex they are. Retrospect does as well as (and in some cases a bit better than) StuffIt in compression. >The behavior under MultiFinder is very good. I can use many applications >while running FBII Ditto for Retrospect. I normally don't bother, but it can be done. >The things I don't like about FBII are: > 1. There's no way to archive a set of files as a set. Retrospect excels here. You can set up subvolumes on your hard disk on a per-folder basis and only back those up. If you want to be more specific or back up specific sets of files, you can write custom scripts to go get them. There are some predefined scripts: older than a week, older than a month, older than six months, text files, etc. If they don't have what you want, you can create custome descriptors to use in the scripts, for instance, all Word or MacWrite or TEXT files, for instance. The scripting is somewhat non-intuitive until you get used to it, but once you do, there's an amazing amount of power -- I don't think you can come up with a rational backup system that couldn't be implemented in their scripts. Another plus: 95% of the time you don't need scripts, and the scripting is the only real non-intuitive piece of the interfave -- and you can ignore it until you need the power. > 2. I've had to do two full restores of my disk, and it's a real > pain. It's fast, but there's no way to save the state of > the entire disk, so files that have been deleted or moved > come back to haunt you. To some degree, the same with Retrospect, but Retrospect allows you to deselect files you don't want restored before you do the restoration, so at least you have the ability to get rid of them before pulling them off the floppies. Retrospect will also only restore the most recent version of a file if you want it to, rather than all versions. > 3. Error recovery is poor. After doing a 100MB backup, I found > that my request to put a copy of the catalog on a floppy > wasn't handled well. Error recovery in Retrospect is pretty good. If a floppy disappears or dies, you can rebuild the catalogs to remove the missing data. If the catalog disappears (it isn't stored on a floppy, although you can create it on a floppy if you want, or copy it there when you're done), Retrospect will recreated it by reading in all the floppies in the set. I threw some know bad floppies at it once and it handled them quite nicely. > anyway, it didn't mark any files as backed up, so my > incremental backups are all being done by restricting the > modification date range. Retrospect is very flexible here. It has a fairly complex way of figuring out what's been changed and what hasn't that looks at # of bytes, modification date and other factors. In fact, it will recognize that file "foo" in folder bar and file "foo" in folder baz are the same file and only copy one (if signature and type match, size matches, date matches, etc..). This can be overridden if you do want duplicates copies. > 4. The documentation is organized like the program, instead > of explaining tasks. The Retrospect documentation is good. The only weak spot is the scripting stuff, which is primarily because it's a complex topic -- you need to work with the program and play with scripts a bit before it all falls into place. -- Chuq Von Rospach <+> chuq@apple.com <+> [This is myself speaking] Rule 1 on how to not get an answer to your question: put "I don't normally read this group" in the message. Rule 2: don't read the group before posting. It's considered bad manners to ask a questio about a topic currently under discussion. -- Uncle chuqui's guide to the net.