1 .\" Revision 1.0 93/06/3 23:00 chk
5 .TH TUNE2FS 8 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
7 tune2fs \- adjust tunable filesystem parameters on second extended filesystems
23 .I interval-between-checks
34 .I reserved-blocks-percentage
38 .I reserved-blocks-count
62 .I last-mounted-directory
66 .RI [^] feature [,...]
75 adjusts tunable filesystem parameters on a Linux second extended filesystem.
78 .BI \-c " max-mount-counts"
79 Adjust the maximal mounts count between two filesystem checks. If
81 is 0 then the number of times the filesystem is mounted will be disregarded
82 by e2fsck and the kernel.
84 .BI \-C " mount-count"
85 Set the number of times the filesystem has been mounted.
86 Can be used in conjunction with -c to force an fsck on
87 the filesystem at the next reboot.
89 .BI \-e " error-behavior"
90 Change the behavior of the kernel code when errors are detected.
92 can be one of the following:
96 Continue normal execution.
99 Remount filesystem read-only.
102 Cause a kernel panic.
106 Set the group which can use reserved filesystem blocks.
109 parameter can be a numerical gid or a group name. If a group name is given,
110 it is converted to a numerical gid before it is stored in the superblock.
112 .B \-i " \fIinterval-between-checks\fR[\fBd\fR|\fBm\fR|\fBw\fR]"
113 Adjust the maximal time between two filesystem checks.
120 in weeks. A value of zero will disable the timedependent checking.
123 Add an ext3 journal to the filesystem. If the
125 option is not specified, the default journal parameters will be used to create
126 an appropriately sized journal (given the size of the filesystem)
127 stored within the filesystem. Note that you must be using a kernel
128 which has ext3 support in order to actually make use of the journal.
130 .BR \-J " journal-options"
131 Override the default ext3 journal parameters. Journal options are comma
132 separated, and may take an argument using the equals ('=') sign.
133 The following journal options are supported:
136 .BI size= journal-size
137 Create a journal stored in the filesystem of size
139 megabytes. The size of the journal must be at least 1024 filesystem blocks
140 (i.e., 1MB if using 1k blocks, 4MB if using 4k blocks, etc.)
141 and may be no more than 102,400 filesystem blocks.
142 There must be enough free space in the filesystem to create a journal of
145 @JDEV@.BI device= external-journal
146 @JDEV@Attach the filesystem to the journal block device located on
147 @JDEV@.IR external-journal .
148 @JDEV@to the filesystem.
150 @JDEV@journal must have been already created using the command
152 @JDEV@.B mke2fs -O journal_dev
153 @JDEV@.IR external-journal.
156 @JDEV@.I external-journal
157 @JDEV@must be formatted with the same block
158 @JDEV@size as filesystems which will be using it.
161 @JDEV@Only one of the
162 @JDEV@.BR size " or " device
163 @JDEV@options can be given for a filesystem.
166 List the contents of the filesystem superblock.
168 .BI \-L " volume-label"
169 Set the volume label of the filesystem.
170 Ext2 filesystem labels can be at most 16 characters long; if
172 is longer than 16 characters,
174 will truncate it and print a warning.
176 .BI \-m " reserved-blocks-percentage"
177 Set the percentage of reserved filesystem blocks.
179 .BI \-M " last-mounted-directory"
180 Set the last-mounted directory for the filesystem.
182 .BR \-O " [^]\fIfeature\fR[,...]"
183 Set or clear the indicated filesystem features (options) in the filesystem.
184 More than one filesystem feature can be cleared or set by separating
185 features with commas. Filesystem features prefixed with a
186 caret character ('^') will be cleared in the filesystem's superblock;
187 filesystem features without a prefix character or prefixed with a plus
188 character ('+') will be added to the filesystem.
190 The following filesystem features can be set or cleared using
195 Limit the number of backup superblocks to save space on large filesystems.
198 Store file type information in directory entries.
201 Create an ext3 journal (as if using the
206 After setting or clearing any filesystem feature,
208 must be run on the filesystem to return the filesystem to a consistent state.
211 Linux kernels before 2.0.39 and many 2.1 series kernels do not support
212 the filesystems that use any of these features.
213 Enabling certain filesystem features may prevent the filesystem from
214 being mounted by kernels which do not support those features.
216 .BI \-r " reserved-blocks-count"
217 Set the number of reserved filesystem blocks.
220 Turn the sparse super feature off or on. Turning this feature on
221 saves space on really big filesystems. This is the same as using the
222 .B "\-O sparse_super"
226 Linux kernels before 2.0.39 do not support this feature. Neither do
227 all Linux 2.1 kernels; please don't use this unless you know what you're
228 doing! You need to run
230 on the filesystem after changing this feature in order to have a valid
234 Set the user who can use the reserved filesystem blocks.
236 can be a numerical uid or a user name. If a user name is given, it
237 is converted to a numerical uid before it is stored in the superblock.
240 Set the universally unique identifier (UUID) of the filesystem to
242 The format of the UUID is a series of hex digits separated by hypthens,
244 "c1b9d5a2-f162-11cf-9ece-0020afc76f16".
247 parameter may also be one of the following:
251 clear the filesystem UUID
254 generate a new randomly-generated UUID
257 generate a new time-based UUID
262 for more information.
263 If the system does not have a good random number generator such as
268 will automatically use a time-based UUID instead of a randomly-generated UUID.
270 We haven't found any bugs yet. That doesn't mean there aren't any...
273 was written by Remy Card <Remy.Card@linux.org>.
275 uses the ext2fs library written by Theodore Ts'o <tytso@mit.edu>.
276 This manual page was written by Christian Kuhtz <chk@data-hh.Hanse.DE>.
277 Timedependent checking was added by Uwe Ohse <uwe@tirka.gun.de>.
280 is part of the e2fsprogs package and is available from
281 http://e2fsprogs.sourceforge.net.