gb7@prism.gatech.EDU (Joe Bradley) (11/02/89)
Someone just stepped into my office and asked me if it was possible to
recover from an accidental reformatting of an internal hard disk under
DOS. Not knowing the answer, I thought I would appeal to the wizards of
the net. They're not even sure of the version of DOS they are running (it's
an old XT). Any pointers to techniques or software which might help
them recover their data would be appreciated.
--
G.J. (Joe) Bradley, Georgia Tech Research Institute, Atlanta, Georgia, 30332
UUCP: ...!{allegra,amd,hplabs,ut-ngp}!gatech!prism!gb7
INTERNET: gb7@prism.gatech.edudavidsen@crdos1.crd.ge.COM (Wm E Davidsen Jr) (11/02/89)
There is no problem recovering from a reformatted hard disk. Just restore from the backup. If a high level format was done (DOS FORMAT command), you may be able to recover some of the data using a package like Norton Utilities. *Do not* put any files back on the disk if you are going to try this, as you will destroy the previous information. How can anyone "accidentally" reformat a hard disk? Virus? -- bill davidsen (davidsen@crdos1.crd.GE.COM -or- uunet!crdgw1!crdos1!davidsen) "The world is filled with fools. They blindly follow their so-called 'reason' in the face of the church and common sense. Any fool can see that the world is flat!" - anon
perry@ccssrv.UUCP (Perry Hutchison) (11/03/89)
In article <2968@hydra.gatech.EDU> gb7@prism.gatech.EDU (Joe Bradley) writes: > Someone just stepped into my office and asked me if it was possible to > recover from an accidental reformatting of an internal hard disk under > DOS ... As I recall, the first package to advertise this ability _without having installed the package before the reformat happened_ was the Mace Utilities (Paul Mace Software, in Ashland, OR). Norton Utilities Advanced Edition may also have that capability by now -- I don't have the manual handy and don't recall for sure. I've never had occasion to attempt this with any package, so cannot make a specific recommendation. I don't think you will need to know the DOS version, but if you do it can usually be found in the boot sector. (At least that will tell you what version formatted the drive.) Once the machine is back in service, do them a favor and rename their format.com to something crazy like fmt@@@.com and create a format.bat consisting of something like fmt@@@ a: so this doesn't happen again.
bruce@mojo.UUCP (Bruce Wahler) (11/04/89)
In article <2968@hydra.gatech.EDU> gb7@prism.gatech.EDU (Joe Bradley) writes: >Someone just stepped into my office and asked me if it was possible to >recover from an accidental reformatting of an internal hard disk under >DOS. Not knowing the answer, I thought I would appeal to the wizards of >the net. They're not even sure of the version of DOS they are running (it's >an old XT). Any pointers to techniques or software which might help >them recover their data would be appreciated. > Try PCTools Deluxe 5.1 or 5.5. They contain a recovery program, which, while designed to work with their MIRROR utility, works fairly well even without it. A word of caution, though: DON'T TOUCH ANYTHING ON THE BAD DISK PRIOR TO RUNNING THE RECOVERY PROGRAM!!! Once you overwrite part of the FAT and/or directory, you will lose part -- if not all -- of your old data. PCTools deluxe can be found in almost any software store, or in Byte and PCMag mail order ads, for around $50 - $60. BAW ---------------------------------------------------------------------------- DISCALIMER: The company I work for, NEC Technologies, Inc., does not endorse PCTools Deluxe. I don't work for Central Point Software, either. I just think their products are well worth the money. ----------------------------------------------------------------------------
tcm@srhqla.SR.COM (Tim Meighan) (11/06/89)
In article <1532@crdos1.crd.ge.COM> davidsen@crdos1.UUCP (bill davidsen) writes: >command), you may be able to recover some of the data using a package >like Norton Utilities. *Do not* put any files back on the disk ifkage Not a chance. A high level format writes $F6 into every byte of every data sector on the disk. Tim Meighan Silent Radio "Get me Premier Kisoff on the hot line!"
wang@m.cs.uiuc.edu (Eric Wang) (11/06/89)
In article <1197@srhqla.SR.COM> tcm@srhqla.SR.COM (Tim Meighan) writes: >In article <1532@crdos1.crd.ge.COM> davidsen@crdos1.UUCP (bill davidsen) writes: > >>command), you may be able to recover some of the data using a package >>like Norton Utilities. *Do not* put any files back on the disk ifkage > >Not a chance. A high level format writes $F6 into every byte of every >data sector on the disk. > >Tim Meighan Then the DOS FORMAT command is NOT high-level, by your definition of the term. IBM just managed to brainwash everybody into thinking that it is. (Among those who also swallowed this line: Peter Norton & Paul Mace.) Mace describes eloquently in his Guide to Data Recovery how he was just goofing around with a new hard disk & noticed information surviving multiple formats, which absolutely staggered him. After several months of intensive work, he added UNFORMAT to his Mace Utilities, and Norton and PC-Tools quickly followed his lead. As a matter of fact, one of the standard methods to recover data from a hard disk on the fritz is to reformat it to clean up the corrupted parts, then unformat it to recover all (?? most, anyways) of the data. Note that the process is not guaranteed to be completely successful, but it's better than losing the whole disk. To clarify this issue: the DOS FORMAT _is_ destructive on FLOPPY disks. If you've formatted a floppy, you can kiss your data good-bye. In fact, Mace's Guide even has a section entitled "Recovery of Data from a Formatted Floppy". It says, basically, "Sorry, you're out of luck. But you can take the time now to replace DOS' FORMAT program with my own FORMAT-F program, so that this problem won't ever happen again." Mace provides a non-destructive FORMAT-F for floppy disks. IBM PC-DOS and Microsoft MS-DOS FORMAT is, as of version 2.x to 3.x, non-destructive on HARD disks. Certain vendors who distribute their own versions of DOS do have FORMATs that are destructive on hard disks, too, but they are in the minority. Eric Wang wang@cs.uiuc.edu
tcm@srhqla.SR.COM (Tim Meighan) (11/07/89)
In article <1197@srhqla.SR.COM> I wrote: > Not a chance. A high level format writes $F6 into every byte of every > data sector on the disk. It has been pointed out to me by several people that this statement is totally *WRONG* when it comes to hard disks. Obviously, I was thinking of floppies, and didn't take the time to verify my own assertions. I hate when that happens. Anyway, thanks to those who mailed corrections to me -- you can stop now! Tim Meighan Silent Radio "Yes! That's right! Everything you know is wrong!"
plim@hpsgpa.HP.COM (Peter Lim) (11/07/89)
> >>command), you may be able to recover some of the data using a package >>like Norton Utilities. *Do not* put any files back on the disk ifkage > >Not a chance. A high level format writes $F6 into every byte of every >data sector on the disk. > I think you are referring to LOW LEVEL format instead of HIGH LEVEL. As far as I can remember, DOS format (which is HIGH LEVEL) is non- destructive on hard disk but destructive on floppy disk. Regards, Peter Lim. HP Singapore IC Design Center. E-mail address: plim@hpsgwg Snail Mail address: Peter Lim Hewlett Packard Singapore, (ICDS, ICS) 1150, Depot Road, Singapore 0410. Telephone: (065)-279-2289
poffen@chomolungma (Russ Poffenberger) (11/08/89)
In article <2968@hydra.gatech.EDU> gb7@prism.gatech.EDU (Joe Bradley) writes: >Someone just stepped into my office and asked me if it was possible to >recover from an accidental reformatting of an internal hard disk under >DOS. Not knowing the answer, I thought I would appeal to the wizards of >the net. They're not even sure of the version of DOS they are running (it's >an old XT). Any pointers to techniques or software which might help >them recover their data would be appreciated. > > >-- Get a copy of Norton Utilities. There is an "unformatting" program that works well. It also has utilities for all sorts of things. I got a copy of the Advanced edition and I love it. It is a little more expensive than the standard edition, but worth it. Russ Poffenberger DOMAIN: poffen@sj.ate.slb.com Schlumberger Technologies UUCP: {uunet,decwrl,amdahl}!sjsca4!poffen 1601 Technology Drive CIS: 72401,276 San Jose, Ca. 95110 (408)437-5254 ------------------------- In a dictatorship, people suffer without complaining. In a democracy, people complain without suffering.
leonard@bucket.UUCP (Leonard Erickson) (11/09/89)
tcm@srhqla.SR.COM (Tim Meighan) writes: >In article <1532@crdos1.crd.ge.COM> davidsen@crdos1.UUCP (bill davidsen) writes: >>command), you may be able to recover some of the data using a package >>like Norton Utilities. *Do not* put any files back on the disk ifkage >Not a chance. A high level format writes $F6 into every byte of every >data sector on the disk. Sorry, but that only happens when you format a floppy disk, or if you have one of 2 or 3 very obscure releases of DOS. A DOS FORMAT of a hard disk will just create an empty directory and FAT and record bad sectors. -- Leonard Erickson ...!tektronix!reed!percival!bucket!leonard CIS: [70465,203] "I'm all in favor of keeping dangerous weapons out of the hands of fools. Let's start with typewriters." -- Solomon Short