| .\" 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 |
| .RI [^] feature [,...] |
| ] |
| [ |
| .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 0 then the number of times the filesystem is mounted will be disregarded |
| by e2fsck and the kernel. |
| .TP |
| .BI \-C " mount-count" |
| Set the number of times the filesystem has been mounted. |
| Can be used in conjunction with -c to force an fsck on |
| the filesystem at the next reboot. |
| .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: |
| .RS 1.2i |
| .TP 1.2i |
| .B continue |
| Continue normal execution. |
| .TP |
| .B remount-ro |
| Remount filesystem read-only. |
| .TP |
| .B panic |
| Cause a kernel panic. |
| .RE |
| .TP |
| .BI \-g " group" |
| Set the group which can use reserved filesystem blocks. |
| The |
| .I group |
| parameter 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 |
| .B \-i " \fIinterval-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. Note that you must be using a kernel |
| which has ext3 support in order to actually make use of the journal. |
| .TP |
| .BR \-J " journal_options" |
| Override the default ext3 journal parameters. Journal options are comma |
| separated, and may take an argument using the equals ('=') sign. |
| The following journal options are supported: |
| .RS 1.2i |
| .TP |
| .BI 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. |
| @JDEV@.TP |
| @JDEV@.BI device= external-journal |
| @JDEV@Add an external journal found on a block device |
| @JDEV@named by |
| @JDEV@.I external-journal |
| @JDEV@to the filesystem. |
| @JDEV@The external |
| @JDEV@journal must have been already created using the command |
| @JDEV@.B mke2fs -O journal_dev |
| @JDEV@.IR journal-device. |
| .RE |
| @JDEV@.IP |
| @JDEV@Only one of the |
| @JDEV@.BR size " or " device |
| @JDEV@options can be given for a filesystem. |
| .TP |
| .B \-l |
| List the contents of the filesystem superblock. |
| .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. |
| .TP |
| .BI \-m " reserved-blocks-percentage" |
| Set the percentage of reserved filesystem blocks. |
| .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. |
| More than one filesystem feature can be cleared or set by separating |
| features with commas. Filesystem features prefixed with a |
| caret character ('^') will be cleared in the filesystem's superblock; |
| filesystem features without a prefix character or prefixed with a plus |
| character ('+') will be added to the filesystem. |
| .IP |
| The following filesystem features can be set or cleared using |
| .BR |
| tune2fs : |
| .RS 1.2i |
| .TP |
| .B sparse_super |
| Limit the number of backup superblocks to save space on large filesystems. |
| .TP |
| .B filetype |
| Store file type information in |
| directory entries. |
| .TP |
| .B has_journal |
| Create an ext3 journal (as if using the |
| .B \-j |
| option). |
| .RE |
| .IP |
| After setting or clearing any filesystem feature, |
| .BR e2fsck (8) |
| must be run on the filesystem to return the filesystem to a |
| consistent state. |
| This option must not be used on mounted filesystems. |
| .IP |
| .B Warning: |
| Linux kernels before 2.0.39 do not support the sparse_super |
| or filetype features; neither do all Linux 2.1 kernels. |
| Enabling certain filesystem features |
| may prevent the filesystem from being mounted on older kernels. |
| .TP |
| .BI \-r " reserved-blocks-count" |
| Set the number of reserved filesystem blocks. |
| .TP |
| .BI \-s " sparse_super_flag" |
| set or reset the sparse_superblock flag. The sparse_super feature |
| saves space on really big filesystems. This is the same as using the |
| .B "\-O sparse_super" |
| option. |
| .IP |
| .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! You need to run |
| .BR e2fsck (8) |
| on the filesystem after changing this feature in order to have a valid |
| filesystem. |
| .TP |
| .BI \-u " user" |
| Set the user who can use the reserved filesystem 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 \-U " UUID" |
| set the universally unique identifier (UUID) of the filesystem to |
| .IR UUID . |
| The format of the UUID is a series of hex digits separated by hypthens, |
| like this: |
| "c1b9d5a2-f162-11cf-9ece-0020afc76f16". |
| The |
| .I UUID |
| parameter may also be one of the following: |
| .RS 1.2i |
| .TP |
| .I clear |
| clear the filesystem UUID |
| .TP |
| .I random |
| generate a new randomly-generated UUID |
| .TP |
| .I time |
| generate a new time-based UUID |
| .RE |
| .IP |
| See |
| .BR uuidgen (8) |
| for more information. |
| If the system does not have a good random number generator such as |
| .I /dev/random |
| or |
| .IR /dev/urandom , |
| .B tune2fs |
| will automatically use a time-based UUID instead of a randomly-generated UUID. |
| .SH BUGS |
| We haven't found any bugs yet. That doesn't mean there aren't any... |
| .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 from anonymous |
| http://e2fsprogs.sourceforge.net. |
| .SH SEE ALSO |
| .BR dumpe2fs (8), |
| .BR e2fsck (8), |
| .BR mke2fs (8) |