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)
       format, 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 © 2007, 2010 Oracle. All rights reserved.