debugfs.ocfs2 man page

debugfs.ocfs2 — OCFS2 file system debugger.

Synopsis

debugfs.ocfs2 [-f cmdfile] [-R command] [-s backup] [-nwV?] [device]

debugfs.ocfs2 -l [tracebit ... [allow|off|deny]] ...

debugfs.ocfs2 -d, --decode lockname

debugfs.ocfs2 -e, --encode lock_type block_num [generation | parent]

Description

The debugfs.ocfs2 program is an interactive file system debugger useful in displaying on-disk OCFS2 filesystem structures on the specified device.

Options

-d, --decode lockname

Display the information encoded in the lockname.

-e, --encode lock_type block_num [generation | parent]

Display the lockname obtained by encoding the arguments provided.

-f, --file cmdfile

Executes the debugfs commands in cmdfile.

-i, --image

Specifies device is an o2image file created by o2image tool.

-l [tracebit ... [allow|off|deny]] ...

Control OCFS2 filesystem tracing by enabling and disabling trace bits. Do debugfs.ocfs2 -l to get the list of all trace bits.

-n, --noprompt

Hide prompt.

-R, --request command

Executes a single debugfs command.

-s, --superblock backup-number

mkfs.ocfs2 makes up to 6 backup copies of the superblock at offsets 1G, 4G, 16G, 64G, 256G and 1T depending on the size of the volume. Use this option to specify the backup, 1 thru 6, to use to open the volume.

-w, --write

Opens the filesystem in RW mode. By default the filesystem is opened in RO mode.

-V, --version

Display version and exit.

-?, --help

Displays help and exit.

Specifying Files

Many debugfs.ocfs2 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.ocfs2. The filespec argument may be specified in two forms. The first form is an inode number or lockname surrounded by angle brackets, e.g., <32>. The second form is a pathname; if the pathname is prefixed by a forward slash ('/'), then it is interpreted relative to the root of the filesystem which is currently opened by debugfs.ocfs2. If not, the path is interpreted relative to the current working directory as maintained by debugfs.ocfs2, which can be modified using the command cd. If the pathname is prefixed by a double forward slash ('//'), then it is interpreted relative to the root of the system directory of the filesystem opened by debugfs.ocfs2.

Locknames

Locknames are specially formatted strings used by the file system to uniquely identify objects in the filesystem. Most locknames used by OCFS2 are generated using the inode number and its generation number and can be decoded using the decode command or used directly in place of an inode number in commands requiring a filespec. Like inode numbers, locknames need to be enclosed in angle brackets, e.g., <M000000000000000040c40c044069cf>. Use the encode command to generate all possible locknames for an object.

Commands

This is a list of the commands which debugfs.ocfs2 supports.

bmap filespec logical_block

Display the physical block number corresponding to the logical block number logical_block in the inode filespec.

cat filespec

Dump the contents of 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 opened filesystem.

controld dump

Display information obtained from ocfs2_controld.

curdev

Show the currently open device.

decode <lockname>

Display the inode number encoded in the lockname.

dirblocks <filespec>

Display the directory blocks associated with the given filespec.

dlm_locks [-f <file>] [-l] [<lockname(s)>]...

Display the status of all lock resources in the o2dlm domain that the file system is a member of. This command expects the debugfs filesystem to be mounted as mount -t debugfs debugfs /sys/kernel/debug. Use lockname(s) to limit the output to the given lock resources, -l to include contents of the lock value block and -f <file> to specify a saved copy of /sys/kernel/debug/o2dlm/<DOMAIN>/locking_state.

dump [-p] filespec outfile

Dump the contents of the inode filespec to the output file outfile. If the -p is given, set the owner, group, timestamps and permissions information on outfile to match those of filespec.

dx_dump filespec

Display the indexed directory information for the given directory.

dx_leaf <block#>

Display the contents of the given indexed directory leaf block.

dx_root <block#>

Display the contents of the given indexed directory root block.

dx_space filespec

Display the directory free space list.

encode filespec

Display the lockname for the filespec.

extent <block#>

Display the contents of the extent structure at block#.

findpath [<lockname>|<inode#>]

Display the pathname for the inode specified by lockname or inode#. This command does not display all the hard-linked paths for the inode.

frag filespec

Display the inode's number of extents to clusters ratio.

fs_locks [-f <file>] [-l] [-B] [<lockname(s)>]...

Display the status of all locks known by the file system. This command expects the debugfs filesystem to be mounted as mount -t debugfs debugfs /sys/kernel/debug. Use lockname(s) to limit the output to the given lock resources, -B to limit the output to only the busy locks, -l to include contents of the lock value block and -f <file> to specify a saved copy of /sys/kernel/debug/ocfs2/<UUID>/locking_state.

group <block#>

Display the contents of the group descriptor at block#.

grpextents <block#>

Display free extents in the chain group.

hb

Display the contents of the heartbeat system file.

help, ?

Print the list of commands understood by debugfs.ocfs2.

icheck block# ...

Display the inodes that use the one or more blocks specified on the command line. If the inode is a regular file, also display the corresponding logical block offset.

lcd directory

Change the current working directory of the debugfs.ocfs2 process to the directory on the native filesystem.

locate [<lockname>|<inode#>] ...

Display all pathnames for the inode(s) specified by locknames or inode#s.

logdump [-T] slot#

Display the contents of the journal for slot slot#. Use -T to limit the output to just the summary of the inodes in the journal.

ls [-l] filespec

Print the listing  of the files in the directory filespec. The -l flag will list files in the long format.

net_stats [-f <file>] [interval [count]]

Display the net statistics. This command expects the debugfs filesystem to be mounted at /sys/kernel/debug. The interval is in seconds. Use the -f parameter to specify a saved copy of /sys/kernel/debug/o2net/stats.

ncheck [<lockname>|<inode#>] ...

See locate.

open device

Open the filesystem on device.

quit, q

Quit debugfs.ocfs2.

rdump [-v] filespec outdir

Recursively dump directory filespec and all its contents (including regular files, symbolic links and other directories) into the outdir which should be an existing directory on the native filesystem.

refcount [-e] filespec

Display the refcount block, and optionally its tree, of the specified inode.

slotmap

Display the contents of the slotmap system file.

stat [-t|-T] filespec

Display the contents of the inode structure for the filespec.  The -t ("traverse") option selects traversal of the inode's metadata. The extent tree, chain list, or other extra metadata will be dumped.  This is the default.  The -T option turns off traversal to reduce the I/O required when basic inode information is needed.

stat_sysdir

Display the contents of all objects in the system directory.

stats [-h] [-s backup-number]

Display the contents of the superblock. Use -s to display a specific backup superblock. Use -h to hide the inode.

xattr [-v] <filespec>

Display extended attributes associated with the given filespec.

Acknowledgement

This tool has been modelled after debugfs, a debugging tool for ext2.

See Also

fsck.ocfs2(8) fsck.ocfs2.checks(8) mkfs.ocfs2(8) mount.ocfs2(8) mounted.ocfs2(8) o2cluster(8) o2image(8) o2info(1) ocfs2(7) tunefs.ocfs2(8)

Author

Oracle Corporation

Referenced By

fsck.ocfs2(8), fsck.ocfs2.checks(8), mkfs.ocfs2(8), mounted.ocfs2(8), mount.ocfs2(8), o2cluster(8), o2image(8), o2info(1), ocfs2(7), tunefs.ocfs2(8).

January 2012 Version 1.8.6 OCFS2 Manual Pages