.\"
.TH DUMPE2FS 8 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
.SH NAME
-dumpe2fs \- dump ext2/ext3 filesystem information
+dumpe2fs \- dump ext2/ext3/ext4 filesystem information
.SH SYNOPSIS
.B dumpe2fs
[
-.B \-bfhixV
+.B \-bfghixV
]
[
-.B \-ob
-.I superblock
+.B \-o superblock=\fIsuperblock
]
[
-.B \-oB
-.I blocksize
+.B \-o blocksize=\fIblocksize
]
.I device
.SH DESCRIPTION
present on
.I device.
.PP
-.B dumpe2fs
-is similar to Berkeley's
-.B dumpfs
-program for the BSD Fast File System.
+.B Note:
+When used with a mounted filesystem, the printed
+information may be old or inconsistent.
.SH OPTIONS
.TP
.B \-b
print the blocks which are reserved as bad in the filesystem.
.TP
-.BI \-ob " superblock"
+.B \-o superblock=\fIsuperblock
use the block
.I superblock
when examining the filesystem.
-This option is not usually needed except by a filesystem wizard who
-is examining the remains of a very badly corupted filesystem.
+This option is not usually needed except by a filesystem wizard who
+is examining the remains of a very badly corrupted filesystem.
.TP
-.BI \-oB " blocksize"
+.B \-o blocksize=\fIblocksize
use blocks of
.I blocksize
bytes when examining the filesystem.
-This option is not usually needed except by a filesystem wizard who
-is examining the remains of a very badly corupted filesystem.
+This option is not usually needed except by a filesystem wizard who
+is examining the remains of a very badly corrupted filesystem.
.TP
.B \-f
-force dumpe2fs to display a filesystem even though it may have some
+force dumpe2fs to display a filesystem even though it may have some
filesystem feature flags which dumpe2fs may not understand (and which
can cause some of dumpe2fs's display to be suspect).
-.TP
+.TP
+.B \-g
+display the group descriptor information in a machine readable colon-separated
+value format. The fields displayed are the group number; the number of the
+first block in the group; the superblock location (or -1 if not present); the
+range of blocks used by the group descriptors (or -1 if not present); the block
+bitmap location; the inode bitmap location; and the range of blocks used by the
+inode table.
+.TP
.B \-h
only display the superblock information and not any of the block
group descriptor detail information.
.TP
.B \-i
-display the filesystem data from an image file created by
+display the filesystem data from an image file created by
.BR e2image ,
-using
+using
.I device
as the pathname to the image file.
.TP
+.B \-m
+If the
+.B mmp
+feature is enabled on the filesystem, check if
+.I device
+is in use by another node, see
+.BR e2mmpstatus (8)
+for full details. If used together with the
+.B \-i
+option, only the MMP block information is printed.
+.TP
.B \-x
print the detailed group information block numbers in hexadecimal format
.TP
.B \-V
-print the version number of
+print the version number of
.B dumpe2fs
and exit.
+.SH EXIT CODE
+.B dumpe2fs
+exits with a return code of 0 if the operation completed without errors.
+It will exit with a non-zero return code if there are any errors, such
+as problems reading a valid superblock, bad checksums, or if the device
+is in use by another node and
+.B -m
+is specified.
.SH BUGS
-You need to know the physical filesystem structure to understand the
+You may need to know the physical filesystem structure to understand the
output.
.SH AUTHOR
-.B dumpe2fs
+.B dumpe2fs
was written by Remy Card <Remy.Card@linux.org>. It is currently being
maintained by Theodore Ts'o <tytso@alum.mit.edu>.
.SH AVAILABILITY
.B dumpe2fs
-is part of the e2fsprogs package and is available from
+is part of the e2fsprogs package and is available from
http://e2fsprogs.sourceforge.net.
.SH SEE ALSO
.BR e2fsck (8),
+.BR e2mmpstatus (8),
.BR mke2fs (8),
-.BR tune2fs (8)
+.BR tune2fs (8).
+.BR ext4 (5)
git://git.whamcloud.com / tools / e2fsprogs.git / blobdiff