e2fsprogs/misc/tune2fs.8.in

.\" Revision 1.0 93/06/3 23:00  chk
.\" Initial revision
.\"
.\"
.TH TUNE2FS 8 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
.SH NAME
tune2fs \- adjust tunable filesystem parameters on second extended filesystems
.SH SYNOPSIS
.B tune2fs
[
.B \-l
]
[
.B \-c
.I max-mount-counts
]
[
.B \-e
.I errors-behavior
]
[
.B \-i
.I interval-between-checks
]
[
.B \-j
.I journal-options
]
[
.B \-m
.I reserved-blocks-percentage
]
[
.B \-r
.I reserved-blocks-count
]
[
.B \-s
.I sparse-super-flag
]
[
.B \-u
.I user
]
[
.B \-g
.I group
]
[
.B \-C
.I mount-count
]
[
.B \-L
.I volume-name
]
[
.B \-M
.I last-mounted-directory
]
[
.B \-O 
\fR[^]\fIfeature\fR[,...]
]
[
.B \-U
.I UUID
]
device
.SH DESCRIPTION
.BI tune2fs
adjusts tunable filesystem parameters on a Linux second extended filesystem.
.SH OPTIONS
.TP
.BI \-c " max-mount-counts"
adjust the maximal mounts count between two filesystem checks.  If 
.I max-mount-counts
is -1 then the number of times the filesystem is mounted will be disregarded
by e2fsck and the kernel.
.TP
.BI \-e " error-behavior"
change the behavior of the kernel code when errors are detected.
.I error-behavior
can be one of the following:
.br
\	continue\	\	Continue normal execution.
.br
\	remount-ro\	Remount filesystem read-only.
.br
\	panic\	\	Cause a kernel panic.
.TP
.BI \-g " group"
set the user group which can benefit from the reserved blocks.
.br
.I group
can be a numerical gid or a group name.  If a group name is given,
it is converted to a numerical gid before it is stored in the superblock.
.TP
.BI \-i " interval-between-checks\fR[\fBd\fR|\fBm\fR|\fBw\fR]"
adjust the maximal time between two filesystem checks. 
No postfix or
.B d
result in days,
.B m
in months, and
.B w
in weeks.  A value of zero will disable the timedependent checking.
.TP
.BR \-j " journal_options"
add a journal inode or device to the filesystem.  
Journal options are comma
separated, and may take an argument using the equals ('=')  sign.
Currently two options are supported,
.I size
and
.IR device .
One these two options must be specified when 
building the journal.
The 
.I size 
option takes a numerical argument which specifies the size of the 
journal in MB (1024*1024 bytes).  Any size between 4MB and 100MB may be used.
Use of this option implies that the journal will be stored in the 
filesystem, so it must be small enough to fit into the filesystem.
The 
.I device
option takes a filename which specifies a block device (external 
to the filesystem) which will contain the external journal.  
.TP
.B \-l
list the contents of the filesystem superblock.
.TP
.BI \-m " reserved-blocks-percentage"
adjust the reserved blocks percentage on the given device.
.TP
.BI \-r " reserved-blocks-count"
adjust the reserved blocks count on the given device.
.TP
.BI \-s " sparse_super_flag"
set or reset the sparse_superblock flag.  The sparse_superblock feature
saves space on really big filesystems.
.B Warning:
The Linux 2.0 kernel does not properly support this feature.  Neither do
all Linux 2.1 kernels; please don't use this unless you know what you're
doing!
.TP
.BI \-u " user"
set the user who can benefit from the reserved blocks.
.I user
can be a numerical uid or a user name.  If a user name is given, it 
is converted to a numerical uid before it is stored in the superblock.
.TP
.BI \-C " mount-count"
set the number of times the filesystem has been mounted.
.TP
.BI \-L " volume-label"
set the volume label of the filesystem.  
Ext2 filesystem labels can be at most 16 characters long; if
.I volume-label 
is longer than 16 characters, 
.B tune2fs
will truncate it and print a warning message.  
.TP
.BI \-M " last-mounted-directory"
set the last-mounted directory for the filesystem.
.TP
.BI \-O " \fR[^]\fIfeature\fR[,...]"
set or clear the indicated filesystem features (options) in the filesystem.
.I Feature
can be one of the following supported filesystem options: 
.IR sparse_super ,
which will cause the filesystem to use sparse superblocks, and
.IR filetype ,
which will cause the filesystem to store file type information in 
directory entries.  After setting or clearing either filesystem feature,
e2fsck must be run on the filesystem.
.TP
.BI \-U " UUID"
set the UUID of the filesystem.  A sample UUID looks like this: 
"c1b9d5a2-f162-11cf-9ece-0020afc76f16".  The uuid may also be
.IR null ,
which will set the filesystem UUID to the null UUID (clearing it), 
.IR random ,
which will generate a new random-based UUID for the filesystem, or
.IR time ,
which will generate a new time-based UUID for the filesystem (see
.BR uuidgen (8)).
.SH BUGS
We haven't found any bugs yet.  That doesn't mean there aren't any...
.SH WARNING
Never use tune2fs to change parameters of a read/write mounted filesystem!
.B Use this utility
.B at your own risk.
You're modifying a filesystem!
.SH AUTHOR
.B tune2fs 
was written by Remy Card <Remy.Card@linux.org>.
.B tune2fs
uses the ext2fs library written by Theodore Ts'o <tytso@mit.edu>.
This manual page was written by Christian Kuhtz <chk@data-hh.Hanse.DE>.
Timedependent checking was added by Uwe Ohse <uwe@tirka.gun.de>.
.SH AVAILABILITY
.B tune2fs
is part of the e2fsprogs package and is available for anonymous 
ftp from tsx-11.mit.edu in /pub/linux/packages/ext2fs.
.SH SEE ALSO
.BR dumpe2fs (8),
.BR e2fsck (8),
.BR mke2fs (8)