jfs_debugfs

jfs_debugfs(8) JFS file system editor jfs_debugfs(8)

NAME

   jfs_debugfs - shell-type JFS file system editor

SYNOPSIS

   jfs_debugfs device

DESCRIPTION

   jfs_debugfs is a program which can be used to perform various low-level actions on a JFS formatted device.

   device is the special file name corresponding to the actual device to be edited (e.g. /dev/hdb1).

   jfs_debugfs must be run as root.

COMMANDS

   a[lter] <block> <offset> <hex_string>
           replaces the data located at the <offset> of <block> with <hex_string>

          <block> is the block number - given in decimal

          <offset> is the offset within that block - given in hexadecimal

          <hex_string> is an even-numbered string of hexadecimal digits to write to the disk

   b[tree] <block> [<offset>]
          * not implemented yet *
           displays one node of the btree located at <offset> of <block> and enters a subcommand mode to navigate the btree

          SUBCOMMANDS:
           l => visit left sibling
           m => modify current node
           p => visit parent node
           r => visit right sibling
           [0-9] => visit the n'th child node
           x => exit subcommand mode

   cb[blfsck]
           displays the area used by ClearBadBlockList for communication with fsck

          SUBCOMMANDS:
           m => modify entries
           x => exit subcommand mode

   dir[ectory] <inode_number> [<file_set>]
           displays the directory entries at <inode_number> and enters subcommand mode

          <inode_number> is the directory's inode - given in decimal

          <file_set> currently must be zero

          SUBCOMMANDS:
           m => modify entries
           x => exit subcommand mode

   d[isplay] [<block> [<offset> [<format> [<count>]]]]
          displays <count> objects located at the <offset> of <block> in <format>

          <block> is the block number - given in decimal

          <offset> is the offset within <block> - given in hexadecimal

          <format> is one of the following:
           a => ascii
           b => block allocation map
           d => decimal
           i => inode
           I => inode allocation map
           s => superblock
           x => hexadecimal
           X => extent allocation descriptor

          <count> is the number of objects to display - given in decimal

   dm[ap]
           displays aggregate disk (block) map

          SUBCOMMANDS
           m => modify map fields
           f => display free count
           t => display tree levels
           x => exit subcommand mode

   dt[ree] <inode_number> [<file_set>]
           displays root of the directory btree located at <inode_number> and enters a subcommand mode to navigate the btree

          <inode_number> is the directory's inode - given in decimal

          <file_set> currently must be zero

          SUBCOMMANDS
           l => visit left sibling
           m => modify current node
           p => visit parent node (not parent directory)
           r => visit right sibling
           [0-9] => visit the n'th child node
           x => exit subcommand mode

   fsckw[sphdr]
           displays the header of the fsck workspace in the aggregate

          SUBCOMMANDS:
           m => modify entries
           x => exit subcommand mode

   h[elp] [<command>]
           displays help for <command>
           if no command is given, all possible commands are displayed

   ia[g] [<IAG_number>] [a | s | <file_set>]
           displays IAG information for <IAG_number> and enters subcommand mode

          <IAG_number> is given in decimal

          a is to use the primary aggregate inode table

          s is to use the secondary aggregate inode table

          <file_set> currently must be zero

          SUBCOMMANDS
           e => display/modify inode extents map
           m => modify IAG
           p => display/modify persistent map
           w => display/modify working map
           x => exit subcommand mode

   i[node] [<inode_number>] [a | s | <file_set>]
           displays inode information for <inode_number> and enters subcommand mode

          <inode_number> is given in decimal

          a is to use the primary aggregate inode table

          s is to use the secondary aggregate inode table

          <file_set> currently must be zero

          SUBCOMMANDS
           a => display/modify inode's ACL
           m => modify inode
           x => exit subcommand mode

   logs[uper]
           displays the journal log superblock and enters subcommand mode

          SUBCOMMANDS
           m => modify journal log superblock
           x => exit subcommand mode

   q[uit]
           exits jfs_debugfs

   se[t] [<variable> <value>]
          * not implemented yet *
           set user-defined <variable> to <value>
           if no arguments are given, displays all set variables

          <variable> must begin with an alphabetic character

   su[perblock] [p | s]
           displays superblock data

          p displays the primary superblock

          s displays the secondary superblock

          SUBCOMMANDS:
           m => modify entries
           x => exit subcommand mode

   s2p[erblock] [p | s]
           displays alternate superblock data

          p displays the primary superblock

          s displays the secondary superblock

          SUBCOMMANDS:
           m => modify entries
           x => exit subcommand mode

   u[nset] <variable>
          * not implemented yet *
           deletes user-defined <variable>

   xt[ree] <inode_number> [<file_set>]
           displays root of the non-directory btree located at <inode_number> and enters a subcommand mode to navigate the btree

          <inode_number> is the directory's inode - given in decimal

          <file_set> currently must be zero

          SUBCOMMANDS
           l => visit left sibling
           m => modify current node
           p => visit parent node (not parent directory)
           r => visit right sibling
           [0-9] => visit the n'th child node
           x => exit subcommand mode

REPORTING BUGS

   If you find a bug in JFS or jfs_debugfs, please report it via the bug tracking system ("Report Bugs" section) of the JFS project web site:
   http://jfs.sourceforge.net/

   Please send as much pertinent information as possible, including the complete output of running jfs_fsck with the -v and -n options on the JFS device.

SEE ALSO

   jfs_fsck(8), jfs_mkfs(8), jfs_fscklog(8), jfs_logdump(8), jfs_tune(8),

AUTHORS

   Barry Arndt  (barndt@us.ibm.com)
   William Braswell, Jr.

   jfs_debugfs is maintained by IBM.
   See the JFS project web site for more details:
   http://jfs.sourceforge.net/

                                                                                   October 29, 2002                                                                         jfs_debugfs(8)