tunefs.ocfs2 - Change OCFS2
file system parameters.
] [ -L volume-label
] [ -Q query-format
] [ --backup-super
is used to adjust OCFS2
file system parameters on
disk. The tool expects the cluster to be online as it needs to take the
appropriate cluster locks to write safely to disk.
- Change the volume UUID (auto-generated) and the label, if
provided, of a cloned OCFS2 volume. This option does not
perform volume cloning. It only changes the UUID and label on a cloned
volume so that it can be mounted on the node that has the original volume
- Turn specific file system features on or off.
tunefs.ocfs2(8) will attempt to enable or disable the feature list
provided. To enable a feature, include it in the list. To disable a
feature, prepend no to the name. For a list of feature names, refer
- -J, --journal-options options
- Modify the journal using options specified on the
command-line. Journal options are comma separated, and may take an
argument using the equals ('=') sign. For a list of possible options,
refer to mkfs.ocfs2(8).
- -L, --label volume-label
- Change the volume label of the file system. Limit the label
to under 64 bytes.
- -N, --node-slots number-of-node-slots
- Valid number ranges from 1 to 255. This number specifies
the maximum number of nodes that can concurrently mount the partition. Use
this to increase or decrease the number of node slots. One reason to
decrease could be to release the space consumed by the journals for those
- -S, --volume-size
- Grow the size of the OCFS2 file system. If
blocks-count is not specified, tunefs.ocfs2(8) extends the
volume to the current size of the device.
- -Q, --query query-format
- Query the file system for its attributes like block size,
label, etc. Query formats are modified versions of the standard printf(3)
formatting. The format is made up of static strings (which may include
standard C character escapes for newlines, tabs, and other special
characters) and printf(3) type formatters. The list of type specifiers is
- B Block size in bytes
- T Cluster size in bytes
- N Number of node slots
- R Root directory block number
- Y System directory block number
- P First cluster group block number
- V Volume label
- U Volume uuid
- M Compat flags
- H Incompat flags
- O RO Compat flags
- -q, --quiet
- Quiet mode.
- -U, --uuid-reset[=new-uuid]
- Reset the volume UUID of the file system. If not provided,
the utility will auto generate it. For custom UUID, specify in either the
plain (2A4D1C581FAA42A1A41D26EFC90C1315) or the traditional
(2a4d1c58-1faa-42a1-a41d-26efc90c1315) format. Users specifying custom
UUIDs must be careful to ensure that no two volumes have the same UUID.
If more than one file system were to have the same UUID, one is
very likely to encounter erratic behavior, if not, outright file
- -v, --verbose
- Verbose mode.
- -V, --version
- Show version and exit.
- -y, --yes
- Always answer Yes in interactive command line.
- -n, --no
- Always answer No in interactive command line.
- Backs up the superblock to fixed offsets (1G, 4G, 16G, 64G,
256G and 1T) on disk. This option is useful for users to backup the
superblock on volumes that the user either explicitly disallowed while
formatting, or, used a version of mkfs.ocfs2(8) (1.2.2 or older)
that did not provide this facility.
- Lists the files having holes. This option is useful when
disabling the sparse feature.
- Updating on-disk cluster information to match the running
cluster. Users looking to update the on-disk cluster stack without
starting the new cluster should use the o2cluster(8) utility.
- During resize, tunefs.ocfs2(8) automatically
determines the size of the given device and grows the file system such
that it uses all of the available space on the device. This optional
argument specifies that the file system should be extended to consume only
the given number of file system blocks on the device.
# tunefs.ocfs2 -Q "UUID = %U\nNumSlots = %N\n" /dev/sda1
UUID = CBB8D5E0C169497C8B52A0FD555C7A3E
NumSlots = 4
debugfs.ocfs2(8) fsck.ocfs2(8) fsck.ocfs2.checks(8)
mkfs.ocfs2(8) mount.ocfs2(8) mounted.ocfs2(8)
o2cluster(8) o2image(8) o2info(1)
Copyright © 2004, 2012 Oracle. All rights reserved.