.\" 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 ] [ .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 .B -j Add an ext3 journal to the filesystem. If the .B \-J option is not specified, the default journal parameters will used will create an appropriately sized journal (given the size of the filesystem) stored within the filesystem. .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 only two (mutually exclusive) options are supported, .I size and .IR device . .TP .BI "\-J size=" journal-size Create a journal stored in the filesystem of size .IR journal-size . The size of the journal must be between 1024 and 10,240 filesystem blocks and there must be sufficient free space in the filesystem to create a journal of that size. .TP .BI "\-J device=" external-journal Add an external journal found on a block device named by .I external-journal to the filesystem. The external journal must have been already created using the command .B mke2fs -O journal_dev .IR journal-device. .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_super feature saves space on really big filesystems. .B Warning: The Linux kernels before 2.0.39 do not 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 . .B tune2fs uses the ext2fs library written by Theodore Ts'o . This manual page was written by Christian Kuhtz . Timedependent checking was added by Uwe Ohse . .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)