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tunefs.ocfs2

NAME

tunefs.ocfs2 - Change OCFS2 file system parameters.

SYNOPSIS

tunefs.ocfs2 [-J journal-options] [-L volume-label] [-M mount-type] [-N number-of-node-slots] [-Q query-format] [-qSUvV] [--backup-super] device [blocks-count]

DESCRIPTION

tunefs.ocfs2 is used to adjust OCFS2 file system parameters on disk. In order to prevent data loss, tunefs.ocfs2 will not perform any action on the specified device if it is mounted on any node in the cluster. This tool requires the O2CB cluster to be online.

OPTIONS

--fs-features=[no]sparse...

Turn specific file system features on or off. tunefs.ocfs2 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. The following features are supported:

sparse

Enable support for sparse files. With this, OCFS2 can avoid allocating (and zeroing) data to fill holes. Available with the file system bundled with Linux kernels 2.6.22 and later.

unwritten

Enable unwritten extents support. With this turned on, an application can request that a range of clusters be pre-allocated within a file. OCFS2 will mark those extents with a special flag so that expensive data zeroing doesn't have to be performed. Reads and writes to a pre-allocated region act as reads and writes to a hole, except a write will not fail due to lack of data allocation. This feature requires sparse file support to be turned on. Available with the file system bundled with Linux kernels 2.6.23 and later.

-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. The following options are supported:

size=journal-size

Grow the size of journal files for all the slots. Minimum size is 4M.

-L, --label volume-label

Change the volume label of the file system. Limit the label to under 64 bytes.

-M, --mount mount-type

Valid types are local and cluster. Local mount allows users to mount the volume without the cluster overhead and works only with OCFS2 bundled with Linux kernels 2.6.20 or later.

-N, --node-slots number-of-node-slots

Use this to increase the number of slots in order to increase the number of nodes that can concurrently mount this volume. The maximum value is 255.

-S, --volume-size

Grow the size of the OCFS2 file system. If blocks-count is not specified, tunefs.ocfs2 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 as follows:

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

Change the volume UUID (auto-generated) for the file system.

-v, --verbose

Verbose mode.

-V, --version

Show version and exit.

--backup-super

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 (1.2.2 or older) that did not provide this facility.

--list-sparse

Lists the files having holes. This option is useful when disabling the sparse feature.

blocks-count

During resize, tunefs.ocfs2 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.

EXAMPLES

[root@node1 ~]# tunefs.ocfs2 -q -Q "BS=%5B\nUUID=%U\n" /dev/sda1
BS= 2048
UUID=80d1adf4-3fde-40dd-9b56-d370462ace17

SEE ALSO

mkfs.ocfs2(8) fsck.ocfs2(8) debugfs.ocfs2(8) mounted.ocfs2(8) ocfs2console(8) o2cb(7)

AUTHORS

Oracle Corporation

COPYRIGHT

Copyright © 2004, 2008 Oracle. All rights reserved.