NAME

       o2info - Dump OCFS2 file system information on disk.

SYNOPSIS

       o2info [-C|--cluster-coherent] [--fs-features] [--volinfo] [--mkfs] <device or file>

DESCRIPTION

       o2info  is designed to be an information tool, to display OCFS2 file system information on
       disk. Its main goal on  one  hand,  is  to  provide  a  tool  to  display  fs  info  in  a
       comprehensive  way  and providing the information which may be missing in debugfs.ocfs and
       tunefs.ocfs2 such as global bitmap free space fragmentation and free inode info  for  each
       slot,  on  the  other hand, it also aims to become a info tool(not an administration one),
       which therefore allows all users who may have no read privilege on the  underlying  device
       to   use   the  utility.  In  practice,  'o2info  /path/to/file/on/ocfs2/vol'  use  a  new
       OCFS2_IOC_INFO ioctl to get info from fs for a mounted case. For  a  privileged  user(e.g,
       root),  the  same  info  however,  can  also  be accessed by 'o2info /dev/sdxN' to direcly
       manipulate the raw device.

OPTIONS

       -C, --cluster-coherent
              Enable cluster (in)coherency for mounted case, means it will attempt to  acquire  a
              global  PR lock when querying info from a cluster filesystem, which may degrade the
              performance, default is none cluster-coherency.

       --fs-features
              List all compat, incompat and ro-compat fs features on OCFS2 filesystem.

       --volinfo
              Dump basic volume information, such as blocksize,  clustersize,  volume  label  and
              UUID etc.

       --mkfs Dump  an  original  format of mkfs.ocfs's arguments, importantly, which can be used
              directly   as    a    fresh    mkfs    retry:    #mkfs.ocfs2    "$(o2info    --mkfs
              /dev/name/or/path/of/file)" /dev/sdaX

       -V, --version
              Show version and exit.

       -h, --help
              Display help and exit.

EXAMPLES

       [oracle@node1 ~]# o2info --volinfo /storage/testfile      # For none-privileged users.
       [root@node1 ~]# o2info --volinfo /dev/sda1
              Label: ocfs2-volume
               UUID: 976D8E630B3A4F1F95497311A92901FC
         Block Size: 4096
       Cluster Size: 4096
         Node Slots: 4
           Features: backup-super strict-journal-super sparse inline-data xattr
           Features: unwritten

SEE ALSO

       debugfs.ocfs2(8) tunefs.ocfs2(8)

AUTHORS

       Oracle Corporation

COPYRIGHT

       Copyright © 2010 Oracle. All rights reserved.