1o2info(1)                     OCFS2 Manual Pages                     o2info(1)
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NAME

6       o2info - Show OCFS2 file system information.
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SYNOPSIS

9       o2info  [-C|--cluster-coherent]  [--fs-features]  [--volinfo]  [--mkfs]
10       [--freeinode]  [--freefrag  chunksize]   [--space-usage]   [--filestat]
11       <device or file>
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DESCRIPTION

15       o2info  shows  information  about  OCFS2  file systems. It differs from
16       debugfs.ocfs2(8) in that it allows users with limited  read  privileges
17       to query similar information. Users do not have to have the read privi‐
18       lege on the device as is expected  by  debugfs.ocfs2(8).  This  utility
19       allows  users  to provide a path to an object on a mounted file system.
20       The user needs to have the read privilege on that object.
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OPTIONS

24       -C, --cluster-coherent
25              Force cluster coherency when querying a  mounted  file  systems.
26              The is disabled by default.  Enable this only if accurate infor‐
27              mation is required as it involves taking cluster locks.
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30       --fs-features
31              Show all the file system features (compat, incompat, ro  compat)
32              enabled on the file system.
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35       --volinfo
36              Show  file  system  information  such  as label, uuid, block and
37              cluster sizes, node slots, etc.
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40       --mkfs Show file system information in mkfs.ocfs2(8) format.
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43       --freeinode
44              Show the inode (allocated/free) count for all slots in the  file
45              system.
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48       --freefrag chunksize
49              Show the free space fragmentation of the file system. The chunk‐
50              size should be equal to or greater than the cluster size.
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53       --space-usage
54              Show the disk space used by a file in block sized units. It also
55              provides  the  block  count  of  the  holes,  shared extents and
56              unwritten extents.
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59       --filestat
60              Show the extended stat(1) information that includes  the  number
61              of  clusters consumed by extended attributes, unwritten extents,
62              shared extents and holes,  along  with  the  file  fragmentation
63              score.
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66       -V, --version
67              Show version and exit.
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70       -h, --help
71              Show help and exit.
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NOTE

75       The utility uses custom info ioctls to query information from a mounted
76       file system. As these info ioctls were added starting in  Linux  kernel
77       2.6.37,  this  utility will not work on mounted OCFS2 file systems run‐
78       ning on systems having older kernels.
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EXAMPLES

82       Non-privileged users can query the volume information by providing  the
83       path  to a file on a mounted file system. Priviledged users can provide
84       the path to the device.
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86           # o2info --volinfo /ocfs2/testfile
87                  Label: webhome
88                   UUID: 8AB016CD59FC4327A2CDAB69F08518E3
89             Block Size: 4096
90           Cluster Size: 131072
91             Node Slots: 8
92               Features: backup-super strict-journal-super sparse extended-slotmap
93               Features: inline-data xattr indexed-dirs refcount discontig-bg clusterinfo
94               Features: unwritten
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96       The same goes for querying file system fragmentation.
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98           # o2info --freefrag 128 /ocfs2/testfile
99           Blocksize: 4096 bytes
100           Clustersize: 131072 bytes
101           Total clusters: 409599
102           Free clusters: 376537 (91.92%)
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104           Min. free extent: 256 KB
105           Max. free extent: 4091648 KB
106           Avg. free extent: 172672 KB
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108           Chunksize: 131072 bytes (1 clusters)
109           Total chunks: 409600
110           Free chunks: 376537 (91.9%)
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112           HISTOGRAM OF FREE EXTENT SIZES:
113           Extent Size Range :  Free extents  Free Clusters  Percent
114             256K...  512K-  :             4            10    0.00%
115             512K... 1024K-  :           251          1179    0.31%
116               1M...    2M-  :             5            72    0.02%
117               8M...   16M-  :             3           288    0.08%
118              32M...   64M-  :             1           447    0.12%
119             128M...  256M-  :             2          3371    0.90%
120               1G...    2G-  :             1         13823    3.67%
121               2G...    4G-  :            12        357347   94.90%
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SEE ALSO

125       debugfs.ocfs2(8)   fsck.ocfs2(8)   fsck.ocfs2.checks(8)   mkfs.ocfs2(8)
126       mount.ocfs2(8) mounted.ocfs2(8) o2cluster(8) o2image(8) tunefs.ocfs2(8)
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AUTHORS

130       Oracle Corporation
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134       Copyright © 2010, 2012 Oracle. All rights reserved.
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138Version 1.8.6                    January 2012                        o2info(1)
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