Command: undelete
UNDELETE attempts the recovery of deleted files.
Syntax:
Basic Syntax:
undelete [path] [/ALL|/LIST] [/Edrive[:directory]]
Prompts to undelete recoverable files from the current working
directory, or from the given path.
directory The location where the file to be undeleted is.
If no directory is given, the current working
directory is assumed.
Advanced Syntax:
undelete [/action] [what] [destination] [optional size]
Options:
/ALL Automatically undelete ALL recoverable files without
prompting first.
/LIST Lists the recoverable files without prompting for
recovery; no action is taken.
/E Exports any undeleted files to an external disk and
optional directory. With this option the source disk
isn't modified.
Possible (advanced) [/action]s:
follow Looks for a deleted file (skips over used clusters!)
starting at the cluster [what] and saves data to a file
given as [destination]. The output of DIRSAVE helps you
to find the right cluster number.
extract Like FOLLOW but follows a still existing file according
to FAT.
dirsave Like all above, but saves a directory to a file.
Directory [what] must be given by absolute path
(starting with \) OR by cluster number. Also shows a
technical directory listing on the screen!
syssave Saves the 1st or 2nd FAT, boot sector or root
directory. No [size] allowed. Select fat1, fat2, boot,
or root in [what]. "Mirror" mode.
size Specifying no [size] or [size] 0 will cause auto-
detection. Unit of [size] is clusters for FOLLOW,
sectors for DIRSAVE. DIRSAVE works the same for both
existing and deleted directories.
destination Must be on a drive other than the current drive. Data
is always read/recovered from the drive from which
undelete is invoked.
Comments:
Using UNDELETE:
1. Finding undeletable files and directories:
Run undelete in DIRSAVE mode. You will see deleted directory
entries specially marked, and you will see their cluster numbers
on the screen. You can redirect screen output to a file, for
example:
undelete /DIRSAVE \ x:\rescued.dir >y:\logfile
Where logfile will contain the screen output.
If you have the FreeDOS utilites installed on your system, you
could use something like one of the following instead:
undelete /DIRSAVE \ x:\rescued.dir | TEE y:\logfile
undelete /DIRSAVE \ x:\rescued.dir | TEE y:\logfile | MORE
These will display the information on screen as well as store it
in the logfile.
2. Recovering an undeletable file:
Find the starting cluster of the file using DIRSAVE, as explained
above. Then use FOLLOW on that cluster, for example:
undelete FOLLOW 1234 x:\rescued.bin
would save the contents of the deleted file starting on cluster
1234 to the file rescued.bin on drive x.
Advanced Uses:
- Recovering from within deleted directories
Run DIRSAVE on an existing directory to find the starting cluster
of the deleted directory. Then run DIRSAVE on that cluster to find
deleted files and directories within the deleted directory... and
so on with successive cluster numbers as required.
- Recovering partially overwritten files
Use FOLLOW on the existing new files and override the size value
(in clusters, undelete tells you how big a cluster on the current
drive is when you start undelete). So, if you have accidentally
overwritten a long file "OLD" with a short new file "NEW":
* find the cluster number of "NEW".
* give the size of "OLD" when using FOLLOW.
* The recovered output will begin with the contents of "NEW" but
should contain the not-overwritten end of "OLD" as well,
hopefully.
- Using undelete to "mirror" important drive data
If your filesystem gets completely broken, you can try to write
back the important data saved by SYSSAVE. The saved information
has to be stored on a separate disk. You may also wish to use the
MIRROR command, which is simpler to use but stores the saved
information at the end of the disk.
* Run undelete in SYSSAVE mode for all 4 sources: fat1, fat2,
boot, root.
* Keep the files in a safe place.
- Restoring the "mirror" data:
This may be necessary in some cases of disk disaster.
WARNING: This is for experts, repair-men and very desperate people
only! Doing this incorrectly or unnecessarily could make things
worse!
* Glue the 4 sources together in the order "boot fat1 fat2 root"
to reconstruct the first part of your partition, starting with
the first sector.
* you could use DEBUG (w command) to restore this info
* You can also merge saved and existing data with a hex editor.
Examples:
- see COMMENTS above -
See also:
debug
del/erase
deltree
format
mirror
more
rd/rmdir
tee
unformat
Copyright © 2003 Eric Auer, updated 2008 and 2022 by W. Spiegl.
This file is derived from the FreeDOS Spec Command HOWTO.
See the file H2Cpying for copying conditions.