Home Man
Search
Today's Posts
Register

Linux & Unix Commands - Search Man Pages

RedHat 9 (Linux i386) - man page for debugfs (redhat section 8)

DEBUGFS(8)			     System Manager's Manual			       DEBUGFS(8)

NAME
       debugfs - ext2 file system debugger

SYNOPSIS
       debugfs	[ -b blocksize ] [ -s superblock ] [ -f cmd_file ] [ -R request ] [ -V ] [ [ -w ]
       [ -c ] [ -i ] [ device ] ]

DESCRIPTION
       The debugfs program is an interactive file system debugger. It can be used to examine  and
       change the state of an ext2 file system.
       device  is  the	special  file corresponding to the device containing the ext2 file system
       (e.g /dev/hdXX).

OPTIONS
       -w     Specifies that the file system should be opened in read-write mode.   Without  this
	      option, the file system is opened in read-only mode.

       -c     Specifies  that the file system should be opened in catastrophic mode, in which the
	      inode and group bitmaps are not read initially.  This can be useful for filesystems
	      with  significant  corruption,  but  because  of this, catastrophic mode forces the
	      filesystem to be opened read-only.

       -i     Specifies that device represents an ext2 image file created by the e2image program.
	      Since  the  ext2	image  file only contains the superblock, block group descriptor,
	      block and inode allocation bitmaps, and the inode table, many debugfs commands will
	      not  function  properly.	 Warning:  no safety checks are in place, and debugfs may
	      fail in interesting ways if commands such as ls, dump, etc. are tried.  debugfs  is
	      a debugging tool.  It has rough edges!

       -b blocksize
	      Forces  the  use of the given block size for the file system, rather than detecting
	      the correct block size as normal.

       -s superblock
	      Causes the file system superblock to be read from the given  block  number,  rather
	      than the default (1).  If you give a -s option, you must also give a -b option.

       -f cmd_file
	      Causes  debugfs  to read in commands from cmd_file, and execute them.  When debugfs
	      is finished executing those commands, it will exit.

       -R request
	      Causes debugfs to execute the single command request, and then exit.

       -V     print the version number of debugfs and exit.

SPECIFYING FILES
       Many debugfs commands take a filespec as an argument to specify an inode (as opposed to	a
       pathname)  in  the filesystem which is currently opened by debugfs.  The filespec argument
       may be specified in two forms.  The first form is an  inode  number  surrounded	by  angle
       brackets, e.g., <2>.  The second form is a pathname; if the pathname is prefixed by a for-
       ward slash ('/'), then it is interpreted relative to the root of the filesystem	which  is
       currently  opened by debugfs.  If not, the pathname is interpreted relative to the current
       working directory as maintained by debugfs.  This may be modified  by  using  the  debugfs
       command cd.

COMMANDS
       This is a list of the commands which debugfs supports.

       cat filespec
	      Dump the contents of the inode filespec to stdout.

       cd filespec
	      Change the current working directory to filespec.

       chroot filespec
	      Change the root directory to be the directory filespec.

       close  Close the currently open file system.

       clri file
	      Clear the contents of the inode file.

       dump [-p] filspec out_file
	      Dump  the  contents  of  the inode filespec to the output file out_file.	If the -p
	      option is given set the owner, group and permissions  information  on  out_file  to
	      match filespec.

       expand_dir filespec
	      Expand the directory filespec.

       feature [fs_feature] [-fs_feature] ...
	      Set  or  clear  various  filesystem  features  in the superblock.  After setting or
	      clearing any filesystem features that were requested, print the  current	state  of
	      the filesystem feature set.

       find_free_block [count [goal]]
	      Find the first count free blocks, starting from goal and allocate it.

       find_free_inode [dir [mode]]
	      Find  a  free inode and allocate it.  If present, dir specifies the inode number of
	      the directory which the inode is to be located.  The second optional argument  mode
	      specifies  the  permissions  of the new inode.  (If the directory bit is set on the
	      mode, the allocation routine will function differently.)

       freeb block [count]
	      Mark the block number block as not allocated.  If the optional  argument	count  is
	      present,	then  count  blocks  starting at block number block will be marked as not
	      allocated.

       freei filespec
	      Free the inode specified by filespec.

       help   Print a list of commands understood by debugfs(8).

       icheck block ...
	      Print a listing of the inodes which use the one or more  blocks  specified  on  the
	      command line.

       initialize device blocksize
	      Create  an  ext2	file system on device with device size blocksize.  Note that this
	      does not fully initialize all of the data structures; to do this, use the mke2fs(8)
	      program.	 This  is  just  a  call  to  the  low-level  library,	which sets up the
	      superblock and block descriptors.

       kill_file filespec
	      Deallocate the inode filespec and its blocks.  Note that this does not  remove  any
	      directory  entries  (if  any)  to this inode.  See the rm(1) command if you wish to
	      unlink a file.

       lcd directory
	      Change the current working directory of the debugfs process  to  directory  on  the
	      native filesystem.

       ln filespec dest_file
	      Create  a  link  named  dest_file  which is a link to filespec.  Note this does not
	      adjust the inode reference counts.

       logdump [-ac] [-b<block>] [-i<inode>] [-f<journal_file>] [output_file]
	      Dump the contents of the ext3 journal.

       ls [-l] [-d] filespec
	      Print a listing of the files in the directory filespec.	The  -l  flag  will  list
	      files  using  a  more verbose format.  The -d flag will list deleted entries in the
	      directory.

       modify_inode filespec
	      Modify the contents of the inode structure in the inode filespec.

       mkdir filespec
	      Make a directory.

       mknod filespec [p|[[c|b] major minor]]
	      Create a special device file (a named pipe, character or block device).  If a char-
	      acter  or  block	device	is to be made, the major and minor device numbers must be
	      specified.

       ncheck inode_num ...
	      Take the requested list of inode numbers, and print a listing of pathnames to those
	      inodes.

       open [-w] [-f] [-i] [-c] [-b blocksize] [-s superblock] device
	      Open  a filesystem for editing.  The -w flag causes the filesystem to be opened for
	      writing.	The -f flag forces the filesystem to be opened even  if  there	are  some
	      unknown  or  incompatible  filesystem  features  which  would  normally prevent the
	      filesystem from being opened.  The -c, -b, -i, and -s options behave  the  same  as
	      those to debugfs itself.

       pwd    Print the current working directory.

       quit   Quit debugfs

       rdump directory destination
	      Recursively  dump directory and all its contents (including regular files, symbolic
	      links, and other directories) into the named destination which should be an  exist-
	      ing directory on the native filesystem.

       rm pathname
	      Unlink  pathname.  If this causes the inode pointed to by pathname to have no other
	      references, deallocate the file.	This command functions	as  the  unlink()  system
	      call.

       rmdir filespec
	      Remove the directory filespec.

       setb block [count]
	      Mark  the  block	number	block  as  allocated.	If the optional argument count is
	      present, then count blocks starting at block number block will be marked	as  allo-
	      cated.

       seti filespec
	      Mark inode filespec as in use in the inode bitmap.

       set_super_value field value
	      Set the superblock field field to value.	The list of valid superblock fields which
	      can be set via this command can be displayed by using the command:  set_super_value
	      -l

       show_super_stats [-h]
	      List  the  contents  of the super block and the block group descriptors.	If the -h
	      flag is given, only print out the superblock contents.

       stat filespec
	      Display the contents of the inode structure of the inode filespec.

       testb block [count]
	      Test if the block number block is marked as allocated in the block bitmap.  If  the
	      optional	argument  count  is  present,  then count blocks starting at block number
	      block will be tested.

       testi filespec
	      Test if the inode filespec is marked as allocated in the inode bitmap.

       unlink pathname
	      Remove the link specified by pathname to an inode.  Note this does not  adjust  the
	      inode reference counts.

       write source_file out_file
	      Create  a  file  in  the	filesystem  named  out_file,  and  copy  the  contents of
	      source_file into the destination file.

AUTHOR
       debugfs was written by Theodore Ts'o <tytso@mit.edu>.

SEE ALSO
       dumpe2fs(8), e2fsck(8), mke2fs(8)

E2fsprogs version 1.32			  November 2002 			       DEBUGFS(8)


All times are GMT -4. The time now is 10:55 PM.

Unix & Linux Forums Content Copyrightę1993-2018. All Rights Reserved.
UNIX.COM Login
Username:
Password:  
Show Password