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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.

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, 2009 Oracle. All rights reserved.