.\"
.TH E2FSCK 8 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
.SH NAME
-e2fsck \- check a Linux ext2/ext3 file system
+e2fsck \- check a Linux ext2/ext3/ext4 file system
.SH SYNOPSIS
.B e2fsck
[
-.B \-pacnyrdfkvstDFSV
+.B \-pacnyrdfkvtDFV
]
[
.B \-b
.I device
.SH DESCRIPTION
.B e2fsck
-is used to check a Linux second extended file system (ext2fs).
-.B E2fsck
-also
-supports ext2 filesystems containing a journal, which are
-also sometimes known as ext3 filesystems, by first applying the journal
-to the filesystem before continuing with normal
+is used to check the ext2/ext3/ext4 family of file systems.
+For ext3 and ext4 filesystems that use a journal, if the system has been
+shut down uncleanly without any errors, normally, after replaying the
+committed transactions in the journal, the file system should be
+marked as clean. Hence, for filesystems that use journalling,
.B e2fsck
-processing. After the journal has been applied, a filesystem will
-normally be marked as clean. Hence, for ext3 filesystems,
-.B e2fsck
-will normally run the journal and exit, unless its superblock
+will normally replay the journal and exit, unless its superblock
indicates that further checking is required.
.PP
.I device
check can be monitored. This option is typically used by programs
which are running
.BR e2fsck .
+If the file descriptor number is negative, then absolute value of
+the file descriptor will be used, and the progress information will be
+suppressed initially. It can later be enabled by sending the
+.B e2fsck
+process a SIGUSR1 signal.
If the file descriptor specified is 0,
.B e2fsck
will print a completion bar as it goes about its business. This requires
filesystem supports directory indexing, or by sorting and compressing
directories for smaller directories, or for filesystems using
traditional linear directories.
+.IP
+Even without the
+.B \-D
+option,
+.B e2fsck
+may sometimes optimize a few directories --- for example, if
+directory indexing is enabled and a directory is not indexed and would
+benefit from being indexed, or if the index structures are corrupted
+and need to be rebuilt. The
+.B \-D
+option forces all directories in the filesystem to be optimized. This can
+sometimes make them a little smaller and slightly faster to search, but
+in practice, you should rarely need to use this option.
+.IP
+The
+.B \-D
+option will detect directory entries with duplicate names in a single
+directory, which e2fsck normally does not enforce for performance reasons.
.TP
.BI \-E " extended_options"
Set e2fsck extended options. Extended options are comma
following options are supported:
.RS 1.2i
.TP
+.BI clone= dup|zero
+Resolve files with shared blocks in pass 1D by giving each file a private
+copy of the blocks (dup);
+or replacing the shared blocks with private, zero-filled blocks (zero).
+The default is dup.
+.TP
+.BI shared= preserve|lost+found|delete
+Files with shared blocks discovered in pass 1D are cloned and then left
+in place (preserve);
+cloned and then disconnected from their parent directory,
+then reconnected to /lost+found in pass 3 (lost+found);
+or simply deleted (delete). The default is preserve.
+.TP
.BI ea_ver= extended_attribute_version
-Assume the format of the extended attribute blocks in the filesystem is
-the specified version number. The version number may be 1 or 2. The
-default extended attribute version format is 2.
+Set the version of the extended attribute blocks which
+.B e2fsck
+will require while checking the filesystem. The version number may
+be 1 or 2. The default extended attribute version format is 2.
+.TP
+.BI journal_only
+Only replay the journal if required, but do not perform any further checks
+or repairs.
+.TP
+.BI inode_badness_threshold= threshold_value
+A badness counter is associated with every inode, which determines the degree
+of inode corruption. Each error found in the inode will increase the badness by
+1 or 2, and inodes with a badness at or above
+.I threshold_value
+will be prompted for deletion. The default
+.I threshold_value
+is 7.
+.TP
+.BI fragcheck
+During pass 1, print a detailed report of any discontiguous blocks for
+files in the filesystem.
+.TP
+.BI discard
+Attempt to discard free blocks and unused inode blocks after the full
+filesystem check (discarding blocks is useful on solid state devices and sparse
+/ thin-provisioned storage). Note that discard is done in pass 5 AFTER the
+filesystem has been fully checked and only if it does not contain recognizable
+errors. However there might be cases where
+.B e2fsck
+does not fully recognize a problem and hence in this case this
+option may prevent you from further manual data recovery.
+.TP
+.BI nodiscard
+Do not attempt to discard free blocks and unused inode blocks. This option is
+exactly the opposite of discard option. This is set as default.
.RE
.TP
.B \-f
Open the filesystem read-only, and assume an answer of `no' to all
questions. Allows
.B e2fsck
-to be used non-interactively. (Note: if the
-.BR \-c ,
-.BR \-l ,
-or
-.B \-L
-options are specified in addition to the
-.B \-n
-option, then the filesystem will be opened read-write, to permit the
-bad-blocks list to be updated. However, no other changes will be made
-to the filesystem.) This option
+to be used non-interactively. This option
may not be specified at the same time as the
.B \-p
or
options.
.TP
.B \-p
-Automatically repair ("preen") the file system. This option will case
+Automatically repair ("preen") the file system. This option will cause
.B e2fsck
to automatically
fix any filesystem problems that can be safely fixed without human
.B \-r
This option does nothing at all; it is provided only for backwards
compatibility.
-.TP
-.B \-s
-This option will byte-swap the filesystem so that it is using the normalized,
-standard byte-order (which is i386 or little endian). If the filesystem is
-already in the standard byte-order,
-.B e2fsck
-will take no action.
-.TP
-.B \-S
-This option will byte-swap the filesystem, regardless of its current
-byte-order.
.TP
.B \-t
Print timing statistics for
.B SIGUSR1
This signal causes
.B e2fsck
-to start displaying a completion bar. (See discussion of the
+to start displaying a completion bar or emitting progress information.
+(See discussion of the
.B \-C
option.)
.TP
.B SIGUSR2
This signal causes
.B e2fsck
-to stop displaying a completion bar.
+to stop displaying a completion bar or emitting progress information.
.SH REPORTING BUGS
Almost any piece of software will have bugs. If you manage to find a
filesystem which causes
.B e2fsck
was written by Theodore Ts'o <tytso@mit.edu>.
.SH SEE ALSO
+.BR e2fsck.conf (5),
.BR badblocks (8),
.BR dumpe2fs (8),
.BR debugfs (8),
git://git.whamcloud.com / tools / e2fsprogs.git / blobdiff