Path: utzoo!utgpu!water!watmath!clyde!att!rutgers!gatech!linus!mbunix!jcmorris
From: jcmorris@mitre-bedford.ARPA (Joseph C. Morris)
Newsgroups: comp.sys.ibm.pc
Subject: Re: backup/restore
Keywords: backup restore xt at pc os dos mdos etc.
Message-ID: <36362@linus.UUCP>
Date: 18 Jul 88 14:35:45 GMT
References: <4808@killer.UUCP>
Sender: news@linus.UUCP
Reply-To: jcmorris@mbunix (Morris)
Distribution: na
Organization: The MITRE Corporation, McLean, VA.
Lines: 27

In article <4808@killer.UUCP> bobc@killer.UUCP (Bob Calbridge) writes:
>           She repeatedly go an error message on the restore cycle stating
>that the "source does not contain backup files."  Since the only files on
>the disk were "backup.001" and "control.001" this seems to be incorrect.
>Is there something inherently incompatible with the two systems?  Could it
>be  a difference between the two versions of BACKUP and RESTORE? 

Exactly.  The DOS 3.3 BACKUP disk format changed; in previous versions one
DOS file was written for each file being backed up; in the new format there
is a data file (backup.nnn) and a control file.  Since you apparently
generated the backup using DOS 3.3 you'll have to use the same level to
do the restore.  I don't know if you can use a 3.3 RESTORE under an earlier
version of DOS.

The apparent reason for the change was the excessive amount of time the
floppy drive spent sawing between the directory and the data files.  This
problem is very apparent when you are restoring a specific file, since a
restore disk written in the old format required that the RESTORE program
read the first record of every file on the disk just to discover that the
disk doesn't contain the file you want.  With the new format this can be
discovered by reading the 'control.nnnn'  file alone.

Also...remember that the files are stored with not only the file name
and extention, but also the path used to access them.  RESTORE will restore
the files only on the identical path.  You cannot, for example, BACKUP a
file 'c:\one\two\sample.dat' and RESTORE it to 'c:\three\sample.dat' since the
paths aren't the same.