.I errors-behavior
]
[
+.B \-f
+]
+[
.B \-i
.I interval-between-checks
]
.RI [^] feature [,...]
]
[
+.B \-T
+.I time-last-checked
+]
+[
.B \-U
.I UUID
]
Cause a kernel panic.
.RE
.TP
+.B \-f
+Force the tune2fs operation to complete even in the face of errors. This
+option is useful when removing the
+.B 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.
+.sp
+.B 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.
+.TP
.BI \-g " group"
Set the group which can use reserved filesystem blocks.
The
option).
.RE
.IP
-After setting or clearing any filesystem feature,
+After setting or clearing
+.B sparse_super
+and
+.B filetype
+filesystem features,
.BR e2fsck (8)
must be run on the filesystem to return the filesystem to a consistent state.
+.B Tune2fs
+will print a message requesting that the system administrator run
+.BR e2fsck (8)
+if necessary.
.IP
.B Warning:
Linux kernels before 2.0.39 and many 2.1 series kernels do not support
on the filesystem after changing this feature in order to have a valid
filesystem.
.TP
+.BI \-T " time-last-checked"
+Set the time the filesystem was last checked using
+.BR 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
+.I time-last-checked
+is the international date format, with an optional time specifier, i.e.
+YYYYMMDD[[HHMM]SS]. The keyword
+.B now
+is also accepted, in which case the last checked time will be set to the
+current time.
+.TP
.BI \-u " user"
Set the user who can use the reserved filesystem blocks.
.I user