DragonFly On-Line Manual Pages

Search: Section:  

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


fsdb -- FFS debugging/editing tool


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


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.


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.


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


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.


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


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

Search: Section: