bmiller@PRC.Unisys.COM (Bruce J. Miller) (01/27/89)
A co-worker was attempting to retrieve some files from floppy which he was told had been created by using BACKUP. Instead of using RESTORE, he used RECOVER. The result was a disk with a directory full of files named "FILExxxx.RES" where xxxx are sequential numbers up to the number of original files on the disk. The original file names appear to be lost; it also appears that the number of bytes in each file has increased slightly. He does not know the original file names nor their order in the directory. Is there any hope of reversing this process, or does he bag it and try to get new copies of the files? Any useful data would be appreciated. (Please don't say "DUMMY!" - we already did that). We are using MS-DOS 3.3; some tools (Norton) are available. Replies via email are OK, or post if you think it's of general interest. Thanks a lot. Bruce Miller (burdvax.prc.unisys.com)
shurr@cbnews.ATT.COM (Larry A. Shurr) (02/01/89)
In article <9077@burdvax.PRC.Unisys.COM> bmiller@PRC.Unisys.COM (Bruce J. Miller) writes: > A co-worker was attempting to retrieve some files from floppy which >he was told had been created by using BACKUP. Instead of using RESTORE, >he used RECOVER. The result was a disk with a directory full of files >named "FILExxxx.RES" where xxxx are sequential numbers up to the number of >original files on the disk. The original file names appear to be lost; it >also appears that the number of bytes in each file has increased slightly. RECOVER is an incredibly brain-damaged utility isn't it? Of course, BACKUP and RESTORE aren't much better. Your friend can probably still restore from that disk as BACKUP stored the original file pathname at the beginning of each backup file on the disk and it is from there that RESTORE gets the file and pathname for each file as it restores them. The files were lengthened by recover because it reset each file size to the exact number of bytes taken up by the each backup file on the disk (i.e. file size now = number of bytes per cluster * number of clusters in the file). The result will probably be that each restore file will have some garbage at the end. Caveat: Beware, different versions of BACKUP and RESTORE may not be compatible. If RESTORE says something like 'Not a backup disk' you are using a version of RESTORE which is not compatible with the ver- sion of BACKUP used to create the disk. Hacker's solution: The versions of BACKUP and RESTORE that I have had to work with use the following format (the incompatibility seems to be in how the sequence file placed on each backup disk is named and what data are written in it): Each backup file consists of: 1) A 128-byte header containing the file's original pathname, followed by 2) the file data. If the a file is split across two or more disks, each segment of the file is stored using the above format. Your job will be to extract each file segment and concatenate them together to recover the original file ("COPY/B" should do it). Go for it. Guarantee: None. Good luck. Regards, Larry -- Signed: Larry A. Shurr (att!cbnews!cbema!las or osu-cis!apr!las) Notice: 'R'eply WILL NOT reach me - try above addresses, OK? Thanks. Clever signature, Wonderful wit, Outdo the others, Be a big hit! - Burma Shave (With apologies to the real thing. Above represents my views only.)
du4@mace.cc.purdue.edu (Ted Goldstein) (02/03/89)
In article <9077@burdvax.PRC.Unisys.COM> bmiller@PRC.Unisys.COM (Bruce J. Miller) writes: >he was told had been created by using BACKUP. Instead of using RESTORE, >he used RECOVER. The result was a disk with a directory full of files >named "FILExxxx.RES" where xxxx are sequential numbers up to the number of >(Please don't say "DUMMY!" - we already did that). We are using MS-DOS 3.3; >some tools (Norton) are available. > Bruce Miller (burdvax.prc.unisys.com) The "disk troubleshooter " book that comes with the new version of Norton utilities contains a detailed explanation of how to recreate your file structure after using the dos recover comand. du4@mace.cc.purdue.edu Ted Goldstein