

 UNDELETE is a utility that  can  be  used  to  recover  deleted  disk  files.
 Recovering deleted disk files is not a sure thing.  When a file  is  deleted,
 its disk space is freed for use by  newly  created  files.  In  general,  the
 sooner after deletion you attempt to  recover  files,  the  greater  is  your
 likelihood of success.

 WARNING!!!   Follow these directions carefully.  This procedure  can  totally
              demolish your disk structure if not  used  properly!  Make  sure
	      you understand what is being done in this procedure,  especially
	      with regard to the DEC utility VFY.

 UNDELETE  attempts to resurrect disk files that have been accidently deleted.
 Files to be recovered are specified using a search pattern similar to the SRD
 Select Entry option:
 
      1.  A question mark or asterisk will match any single character;
      2.  Stem searches are performed for the file name and type fields;  and
      3.  Any unspecified fields default to a wild card search.
 
      The special version numbers, 0 and -1, are not supported.
 
 Whenever a matched file header is found, its file ID is printed,  along  with
 a PIP-like listing of the file owner, file specification, size  and  creation
 date.  This information will be helpful in returning the file to  the  proper
 directory (usually the owner's UFD).
 
      The procedure to follow is:
 
      1.  Log on to a privileged account, preferably on a hardcopy terminal.
 
      2.  Immediately halt all activity on the disk and DMOunt it.
 
      3.  ALLocate the disk to yourself  and  MOUnt  it  with  the  index file
          unlocked (/UNL).
 
      4.  Run UNDELETE and provide the name of the disk and the search pattern
          ( RUN $UNDELETE )
 
      5.  Run VFY (/UP and /LO options) with the  listing  and  scratch  files
          directed to another disk.  (The listing file may get rather  lengthy
          if lots of disk blocks were deleted, so you may  want  to  send  the
          listing to a disk or NL:.)  (VFY requires  that  the  UIC  [1, 3] be
          present on the disk being recovered.  UNDELETE will prompt you  with
          the command lines to use for VFY when UNDELETE completes step 4.)
 
      6.  Rename the recovered files from [1,3] to  their  proper directories.
          (Warning: recover all files before renaming, or copy them to another
          medium one directory at a time.  If you guess wrong  at  the  proper
          UFD, it could be extended to accommodate the new  directory  entries
	  and re-use a disk block from one of the files yet to be recovered.)
  
       7.  If there are extra recovered files that you want to  delete  again,
           be  sure to rebuild the volume bit map again to take care of doubly
           allocated disk blocks before returning it to service  (the /RE  and
	   /UP options in VFY).
  
       8.  Always VFY the disk one last time before putting it back on-line!
  
       9.  When you're satisfied everything is OK, return the disk back to its
           original state (PUBLIC, /-UNL, etc.).
