o2image(8) OCFS2 Manual Pages o2image(8)NAME
o2image - Copy or restore OCFS2 file system meta-data
SYNOPSIS
o2image [-r] [-I] device image-file
DESCRIPTION
o2image copies the OCFS2 file system meta-data from the device to the specified image-file. This image file contains the file system
skeleton that includes the inodes, directory names and file names. It does not include any file data.
This image file can be useful to debug certain problems that are not reproducible otherwise. Like on-disk corruptions. It could also be
used to analyse the file system layout in an aging file system with an eye towards improving performance.
As the image-file contains a copy of all the meta-data blocks, it can be a large file. By default, it is created in a packed format, in
which all meta-data blocks are written back-to-back. With the -r option, the user could choose to have the file in the raw (or sparse) for-
mat, in which the blocks are written to the same offset as they are on the device.
debugfs.ocfs2 understands both formats.
o2image also has the option, -I, to restore the meta-data from the image file onto the device. This option will rarely be useful to end-
users and has been written specifically for developers and testers.
OPTIONS -r Copies the meta-data to the image-file in the raw format. Use this option only if the destination file system supports sparse files.
If unsure, do not use this option and let the tool create the image-file in the packed format.
-I Restores meta-data from the image-file onto the device. CAUTION: This option could corrupt the file system.
-i Interactive mode - before writing out the image file print it's size and ask whether to proceed. This setting only applies when '-I'
is not specified. It can be useful when the file system holding the image is low on disk space and the user might need to free up
space once the target image size is calculated.
EXAMPLES
[root@node1 ~]# o2image /dev/sda1 sda1.out
Copies metadata blocks from /dev/sda1 device to sda1.out file
[root@node1 ~] o2image -I /dev/sda1 sda1.out
Use with CAUTION. Copies meta-data blocks from sda1.out onto the
/dev/sda1 device.
SEE ALSO debugfs.ocfs2(8)fsck.ocfs2(8)AUTHORS
Oracle Corporation
COPYRIGHT
Copyright (C) 2007, 2010 Oracle. All rights reserved.
Version 1.6.4 September 2010 o2image(8)
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debugfs.ocfs2(8) OCFS2 Manual Pages debugfs.ocfs2(8)NAME
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 upto 6 backup copies of the superblock at offsets 1G, 4G, 16G, 64G, 256G and 1T depending on the size of the vol-
ume. 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 cur-
rently opened by debugfs.ocfs2. The filespec argument may be specified in two forms. The first form is an inode number or lockname sur-
rounded 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>. To generate a lockname for a given object, use the encode command.
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/ker-
nel/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 permis-
sions information on outfile to match those of filespec.
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/ker-
nel/debug/ocfs2/<UUID>/locking_state.
group block#
Display the contents of the group descriptor at block#.
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 node#
Display the contents of the journal for node node#.
ls [-l] filespec
Print the listing of the files in the directory filespec. The -l flag will list files in the long format.
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 filespec
Display the contents of the inode structure for the filespec.
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 mkfs.ocfs2(8)fsck.ocfs2(8)tunefs.ocfs2(8)mounted.ocfs2(8)ocfs2console(8)o2image(8)o2cb(7)AUTHOR
Oracle Corporation
COPYRIGHT
Copyright (C) 2004, 2010 Oracle. All rights reserved.
Version 1.4.3 February 2010 debugfs.ocfs2(8)