| Tag | Description |
|---|
| |
| Tag | Description |
|---|
|
continue |
Continue normal execution.
|
|
remount-ro |
Remount filesystem read-only.
|
|
panic |
Cause a kernel panic.
|
|
|
-f |
Force the tune2fs operation to complete even in the face of errors. This
option is useful when removing the
has_journal filesystem feature from a filesystem which has
an external journal (or is corrupted
such that it appears to have an external journal), but that
external journal is not available.
WARNING: Removing an external journal from a filesystem which was not cleanly unmounted
without first replaying the external journal can result in
severe data loss and filesystem corruption.
|
|
-g group |
Set the group which can use reserved filesystem blocks.
The
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.
|
|
-i interval-between-checks[d|m|w] |
| |
Adjust the maximal time between two filesystem checks.
No postfix or
d result in days,
m in months, and
w in weeks. A value of zero will disable the time-dependent checking.
It is strongly recommended that either
-c (mount-count-dependent) or
-i (time-dependent) checking be enabled to force periodic full
e2fsck(8)
checking of the filesystem. Failure to do so may lead to filesystem
corruption due to bad disks, cables, memory, or kernel bugs to go
unnoticed until they cause data loss or corruption.
|
|
-j |
Add an ext3 journal to the filesystem. If the
-J option is not specified, the default journal parameters will be used to 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.
|
|
|
If this option is used to create a journal on a mounted filesystem, an
immutable file,
.journal, will be created in the top-level directory of the filesystem, as it is
the only safe way to create the journal inode while the filesystem is
mounted. While the ext3 journal is visible, it is not safe to
delete it, or modify it while the filesystem is mounted; for this
reason the file is marked immutable.
While checking unmounted filesystems,
e2fsck(8)
will automatically move
.journal files to the invisible, reserved journal inode. For all filesystems
except for the root filesystem, this should happen automatically and
naturally during the next reboot cycle. Since the root filesystem is
mounted read-only,
e2fsck(8)
must be run from a rescue floppy in order to effect this transition.
|
|
|
On some distributions, such as Debian, if an initial ramdisk is used,
the initrd scripts will automatically convert an ext2 root filesystem
to ext3 if the
/etc/fstab file specifies the ext3 filesystem for the root filesystem in order to
avoid requiring the use of a rescue floppy to add an ext3 journal to
the root filesystem.
|
|
-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:
|
| |
| Tag | Description |
|---|
|
size=journal-size | | |
Create a journal stored in the filesystem of size
journal-size megabytes. The size of the journal must be at least 1024 filesystem blocks
(i.e., 1MB if using 1k blocks, 4MB if using 4k blocks, etc.)
and may be no more than 102,400 filesystem blocks.
There must be enough free space in the filesystem to create a journal of
that size.
|
|
device=external-journal | | |
Attach the filesystem to the journal block device located on
external-journal. The external
journal must have been already created using the command
|
|
|
mke2fs -O journal_dev external-journal |
|
|
Note that
external-journal must be formatted with the same block
size as filesystems which will be using it.
In addition, while there is support for attaching
multiple filesystems to a single external journal,
the Linux kernel and
e2fsck(8)
do not currently support shared external journals yet.
|
|
|
Instead of specifying a device name directly,
external-journal can also be specified by either
LABEL=label or
UUID=UUID to locate the external journal by either the volume label or UUID
stored in the ext2 superblock at the start of the journal. Use
dumpe2fs(8)
to display a journal device’s volume label and UUID. See also the
-L option of
tune2fs(8).
|
|
|
|
Only one of the
size or device options can be given for a filesystem.
|
|
-l |
List the contents of the filesystem superblock.
|
|
-L volume-label |
| |
Set the volume label of the filesystem.
Ext2 filesystem labels can be at most 16 characters long; if
volume-label is longer than 16 characters,
tune2fs will truncate it and print a warning. The volume label can be used
by
mount(8),
fsck(8),
and
/etc/fstab(5)
(and possibly others) by specifying
LABEL=volume_label instead of a block special device name like
/dev/hda5. |
|
-m reserved-blocks-percentage |
| |
Set the percentage of reserved filesystem blocks.
|
|
-M last-mounted-directory |
| |
Set the last-mounted directory for the filesystem.
|
|
-o [^]mount-option[,...] |
| |
Set or clear the indicated default mount options in the filesystem.
Default mount options can be overridden by mount options specified
either in
/etc/fstab(5)
or on the command line arguments to
mount(8).
Older kernels may not support this feature; in particular,
kernels which predate 2.4.20 will almost certainly ignore the
default mount options field in the superblock.
|
|
|
More than one mount option can be cleared or set by separating
features with commas. Mount options prefixed with a
caret character (’^’) will be cleared in the filesystem’s superblock;
mount options without a prefix character or prefixed with a plus
character (’+’) will be added to the filesystem.
|
|
|
The following mount options can be set or cleared using
tune2fs: |
| |
| Tag | Description |
|---|
|
debug |
Enable debugging code for this filesystem.
|
|
bsdgroups | | |
Emulate BSD behaviour when creating new files: they will take the group-id
of the directory in which they were created. The standard System V behaviour
is the default, where newly created files take on the fsgid of the current
process, unless the directory has the setgid bit set, in which case it takes
the gid from the parent directory, and also gets the setgid bit set if it is
directory itself.
|
|
user_xattr | | |
Enable user-specified extended attributes.
|
|
acl |
Enable Posix Access Control Lists.
|
|
uid16 |
Disables 32-bit UIDs and GIDs. This is for interoperability with
older kernels which only store and expect 16-bit values.
|
|
journal_data | | |
When the filesystem is mounted with journalling enabled, all data
(not just metadata) is committed into the journal prior to being written
into the main filesystem.
|
|
journal_data_ordered | | |
When the filesystem is mounted with journalling enabled, all data is forced
directly out to the main file system prior to its metadata being committed
to the journal.
|
|
journal_data_writeback | | |
When the filesystem is mounted with journalling enabled, data may be
written into the main filesystem after its metadata has been committed
to the journal. This may increase throughput, however, it may allow old
data to appear in files after a crash and journal recovery.
|
|
|
-O [^]feature[,...] |
| |
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.
|
|
|
The following filesystem features can be set or cleared using
tune2fs: |
| |
| Tag | Description |
|---|
|
dir_index | | |
Use hashed b-trees to speed up lookups in large directories.
|
|
filetype | | |
Store file type information in directory entries.
|
|
has_journal | | |
Use a journal to ensure filesystem consistency even across unclean shutdowns.
Setting the filesystem feature is equivalent to using the
-j option.
|
|
sparse_super | | |
Limit the number of backup superblocks to save space on large filesystems.
|
|
|
|
After setting or clearing
sparse_super and
filetype filesystem features,
e2fsck(8)
must be run on the filesystem to return the filesystem to a consistent state.
Tune2fs will print a message requesting that the system administrator run
e2fsck(8)
if necessary. After setting the
dir_index feature,
e2fsck -D can be run to convert existing directories to the hashed B-tree format.
|
|
|
Warning: Linux kernels before 2.0.39 and many 2.1 series kernels do not support
the filesystems that use any of these features.
Enabling certain filesystem features may prevent the filesystem from
being mounted by kernels which do not support those features.
|
|
-r reserved-blocks-count |
| |
Set the number of reserved filesystem blocks.
|
|
-s [0|1] |
Turn the sparse super feature off or on. Turning this feature on
saves space on really big filesystems. This is the same as using the
-O sparse_super option.
|
|
|
Warning: 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
e2fsck(8)
on the filesystem after changing this feature in order to have a valid
filesystem.
|
|
-T time-last-checked |
| |
Set the time the filesystem was last checked using
e2fsck. This can be useful in scripts which use a Logical Volume Manager to make
a consistent snapshot of a filesystem, and then check the filesystem
during off hours to make sure it hasn’t been corrupted due to
hardware problems, etc. If the filesystem was clean, then this option can
be used to set the last checked time on the original filesystem. The format
of
time-last-checked is the international date format, with an optional time specifier, i.e.
YYYYMMDD[[HHMM]SS]. The keyword
now is also accepted, in which case the last checked time will be set to the
current time.
|
|
-u user |
Set the user who can use the reserved filesystem blocks.
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.
|
|
-U UUID |
Set the universally unique identifier (UUID) of the filesystem to
UUID. The format of the UUID is a series of hex digits separated by hyphens,
like this:
"c1b9d5a2-f162-11cf-9ece-0020afc76f16".
The
UUID parameter may also be one of the following:
|
| |
| Tag | Description |
|---|
|
clear |
clear the filesystem UUID
|
|
random |
generate a new randomly-generated UUID
|
|
time |
generate a new time-based UUID
|
|
|
|
The UUID may be used by
mount(8),
fsck(8),
and
/etc/fstab(5)
(and possibly others) by specifying
UUID=uuid instead of a block special device name like
/dev/hda1. |
|
|
See
uuidgen(8)
for more information.
If the system does not have a good random number generator such as
/dev/random or
/dev/urandom, tune2fs will automatically use a time-based UUID instead of a randomly-generated UUID.
|
