1o2info(1) OCFS2 Manual Pages o2info(1)
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6 o2info - Show OCFS2 file system information.
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9 o2info [-C|--cluster-coherent] [--fs-features] [--volinfo] [--mkfs]
10 [--freeinode] [--freefrag chunksize] [--space-usage] [--filestat]
11 <device or file>
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15 o2info shows information about OCFS2 file systems. It differs from
16 debugfs.ocfs2(8) in that it allows users with limited read priviledges
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 priviledge on that object.
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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.
28 --fs-features
31 Show all the file system features (compat, incompat, ro compat)
32 enabled on the file system.
33 --volinfo
36 Show file system information such as label, uuid, block and
37 cluster sizes, node slots, etc.
38 --mkfs Show file system information in mkfs.ocfs2(8) format.
41 --freeinode
44 Show the inode (allocated/free) count for all slots in the file
45 system.
46 --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.
51 --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.
57 --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.
64 -V, --version
67 Show version and exit.
68 -h, --help
71 Show help and exit.
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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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82 Non-priviledged 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.
85 # 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
95 The same goes for querying file system fragmentation.
97 # o2info --freefrag 128 /ocfs2/testfile
99 Blocksize: 4096 bytes
100 Clustersize: 131072 bytes
101 Total clusters: 409599
102 Free clusters: 376537 (91.92%)
103 Min. free extent: 256 KB
105 Max. free extent: 4091648 KB
106 Avg. free extent: 172672 KB
107 Chunksize: 131072 bytes (1 clusters)
109 Total chunks: 409600
110 Free chunks: 376537 (91.9%)
111 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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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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130 Oracle Corporation
131
134 Copyright © 2010, 2012 Oracle. All rights reserved.
135Version 1.8.5 January 2012 o2info(1)