DragonFly On-Line Manual Pages

FSDB(8)                DragonFly System Manager's Manual               FSDB(8)

NAME
     fsdb -- FFS debugging/editing tool

SYNOPSIS
     fsdb [-d] [-f] [-r] fsname

DESCRIPTION
     The fsdb utility opens fsname (usually a raw disk partition) and runs a
     command loop allowing manipulation of the file system's inode data.  You
     are prompted to enter a command with fsdb (inum X)> where X is the
     currently selected i-number.  The initial selected inode is the root of
     the file system (i-number 2).  The command processor uses the editline(3)
     library, so you can use command line editing to reduce typing if desired.
     When you exit the command loop, the file system superblock is marked
     dirty and any buffered blocks are written to the file system.

     The following options are available:

     -d      Enable additional debugging output (which comes primarily from
             fsck(8)-derived code).

     -f      Left for historical reasons and has no meaning.

     -r      Open the file system read/only, and disables all commands that
             would write to it.

COMMANDS
     Besides the built-in editline(3) commands, fsdb supports these commands:

     help    Print out the list of accepted commands.

     inode i-number
             Select inode i-number as the new current inode.

     back    Revert to the previously current inode.

     clri i-number
             Clear i-number.

     lookup name
     cd name
             Find name in the current directory and make its inode the current
             inode.  Name may be a multi-component name or may begin with
             slash to indicate that the root inode should be used to start the
             lookup.  If some component along the pathname is not found, the
             last valid directory encountered is left as the active inode.
             This command is valid only if the starting inode is a directory.

     active
     print   Print out the active inode.

     blocks  Print out the block list of the active inode.  Note that the
             printout can become long for large files, since all indirect
             block pointers will also be printed.
     uplink  Increment the active inode's link count.

     downlink
             Decrement the active inode's link count.

     linkcount number
             Set the active inode's link count to number.

     ls      List the current inode's directory entries.  This command is
             valid only if the current inode is a directory.

     rm name
     del name
             Remove the entry name from the current directory inode.  This
             command is valid only if the current inode is a directory.

     ln ino name
             Create a link to inode ino under the name name in the current
             directory inode.  This command is valid only if the current inode
             is a directory.

     chinum dirslot inum
             Change the i-number in directory entry dirslot to inum.

     chname dirslot name
             Change the name in directory entry dirslot to name.  This command
             cannot expand a directory entry.  You can only rename an entry if
             the name will fit into the existing directory slot.

     chtype type
             Change the type of the current inode to type.  Type may be one
             of: file, dir, socket, or fifo.

     chmod mode
             Change the mode bits of the current inode to mode.  You cannot
             change the file type with this subcommand; use chtype to do that.

     chflags flags
             Change the file flags of the current inode to flags.

     chown uid
             Change the owner of the current inode to uid.

     chgrp gid
             Change the group of the current inode to gid.

     chgen gen
             Change the generation number of the current inode to gen.

     mtime time
     ctime time
     atime time
             Change the modification, change, or access time (respectively) on
             the current inode to time.  Time should be in the format
             YYYYMMDDHHMMSS[.nsec] where nsec is an optional nanosecond
             specification.  If no nanoseconds are specified, the mtimensec,
             ctimensec, or atimensec field will be set to zero.

     quit, q, exit, <EOF>
             Exit the program.

SEE ALSO
     editline(3), fs(5), clri(8), fsck(8)

HISTORY
     The fsdb utility appeared in 4.3BSD-Tahoe.  It used the soure code for
     fsck(8) to implement most of the file system manipulation code.  The
     remainder of fsdb appeared in NetBSD 1.1 written by John T. Kohl.  It
     first appeared in FreeBSD 2.1.5 ported by Peter Wemm.

WARNING
     Use this tool with extreme caution--you can damage an FFS file system
     beyond what fsck(8) can repair.

BUGS
     Manipulation of ``short'' symlinks doesn't work (in particular, don't try
     changing a symlink's type).

     You must specify modes as numbers rather than symbolic names.

     There are a bunch of other things that you might want to do which fsdb
     doesn't implement.

DragonFly 4.5                 September 29, 2016                 DragonFly 4.5