[Cluster-devel] cluster/gfs/man gfs_edit.8

Thu Oct 11 16:47:36 UTC 2007

CVSROOT:	/cvs/cluster
Module name:	cluster
Branch: 	RHEL5
Changes by:	rpeterso at sourceware.org	2007-10-11 16:47:36

Added files:
	gfs/man        : gfs_edit.8 

Log message:
	Resolves: bz 295301: Need man page for gfs_edit

Patches:
http://sourceware.org/cgi-bin/cvsweb.cgi/cluster/gfs/man/gfs_edit.8.diff?cvsroot=cluster&only_with_tag=RHEL5&r1=NONE&r2=1.1.2.1

/cvs/cluster/cluster/gfs/man/gfs_edit.8,v  -->  standard output
revision 1.1.2.1

--- cluster/gfs/man/gfs_edit.8
+++ -	2007-10-11 16:47:36.320051000 +0000
@@ -0,0 +1,130 @@
+.\"  Copyright (C) 2007 Red Hat, Inc.  All rights reserved.
+
+.TH gfs_edit 8
+
+.SH NAME
+gfs_edit - Display or edit GFS internal structures.
+
+.SH SYNOPSIS
+.B gfs_edit
+[\fIOPTION\fR]... \fIDEVICE\fR
+
+.SH DESCRIPTION
+The gfs_edit command is a tool used to examine, edit or display internal
+data structures of a GFS filesystem.  Use at your own risk.
+
+.SH OPTIONS
+.TP
+\fB-V\fP
+Print program version information only.
+
+.SH INTERACTIVE MODE
+There are three display modes: hex mode, structure mode and pointers mode.
+You use the m key to switch between the modes, as described below.
+The modes are as follows:
+.TP
+Hex mode (default)
+Display or edit blocks of the file system in hexadecimal and ascii.
+
+Lines at the top indicate the currently displayed block number in hex.
+If the block contains a GFS data structure, the name of that
+structure will appear in the upper right corner of the display.
+If the block is a well-known block, such as the superblock or rindex,
+there will be a line to indicate what it is.
+
+In hex mode, you can edit blocks by pressing \fB<enter>\fP and entering
+hexadecimal digits to replace the highlighted hex digits.  Do NOT precede
+the numbers with "0x".  For example, if you want to change the value at
+offset 0x60 from a 0x12 to 0xef, position your cursor to offset 0x60,
+so that the 12 is highlighted, then press \fB<enter>\fP and type in "ef".
+You will automatically be returned to display mode (Unlike gfs2_edit,
+you may only edit one byte at a time.)
+
+In hex mode, different colors indicate different things.
+For example, an inode will appear white, block offsets will be light
+blue, and actual data (anything after the gfs data structure) will be red.
+
+.TP
+Structure mode
+Decode the file system block into its GFS structure and
+display the values of that structure.  This mode is most useful for
+jumping around the file system.  For example, you can use the arrow 
+keys to position down to a pointer and press \fBJ\fP to jump to that block.
+
+.TP
+Pointers mode
+Display any additional information appearing on the block.
+For example, if an inode has block pointers, this will display them and
+allow you to scroll through them.  You can also position to one of them
+and press \fBJ\fP to jump to that block.
+
+.SH Interactive mode command keys:
+.TP
+\fBq\fP or \fB<esc>\fP
+The \fBq\fP or \fB<escape>\fP keys are used to exit gfs_edit.
+
+.TP
+\fB<arrow/movement keys>\fP up, down, right, left, pg-up, pg-down, home, end
+The arrow keys are used to highlight an area of the display.  The \fBJ\fP
+key may be used to jump to the block that is highlighted.
+
+.TP
+\fBm\fP - Mode switch
+The \fBm\fP key is used to switch between the three display modes.
+The initial mode is hex mode.  Pressing the \fBm\fP key once switches to
+structure mode.  Pressing it a second time switches from structure mode
+to pointers mode.  Pressing it a third time takes you back to hex mode again.
+
+.TP
+\fBj\fP - Jump to block
+The \fBj\fP key jumps to the block number that is currently highlighted.
+In hex mode, hitting J will work when any byte of the pointer is highlighted.
+
+.TP
+\fBg\fP - Goto block
+The \fBg\fP key asks for a block number, then jumps there.  Note that
+in many cases, you can also arrow up so that the current block number
+is highlighted, then press \fB<enter>\fP to enter a block number to jump to
+in hexadecimal, with no leading "0x".
+
+.TP
+\fBh\fP - Help display
+The \fBh\fP key causes the interactive help display to be shown.
+
+.TP
+\fBf\fP or \fB<space>\fP - Forward block
+The \fBf\fP key causes you to scroll forward one block.
+
+.TP
+\fBb\fP - Backward block
+The \fBb\fP key causes you to scroll backward one block.
+
+.TP
+\fB<home>\fP - Return to superblock
+The \fB<home>\fP key takes you back to the superblock.
+
+.TP
+\fB<backspace>\fP
+This takes you back to the block you were displaying previously.
+Unlike gfs2_edit, gfs_edit only remembers the one block you previously viewed.
+
+.SH EXAMPLES
+.TP
+gfs_edit /dev/vg0/lvol0
+This will display the superblock of the gfs file system located on
+/dev/vg0/lvol0 and allow you to edit.
+
+.SH KNOWN LIMITATIONS
+.TP
+Shortcomings compared to gfs2_edit
+Unlike gfs2_edit, gfs_edit cannot print data structures.  There is no
+alternate color scheme.  It does not remember multiple block jumps,
+and it can not parse the rindex file and other data structures.
+It only operates on file systems with the default 4K block size.
+It does not work with gfs2 file systems.
+
+Since this is primarily a debugging tool and since gfs2_edit can do
+more than gfs_edit can, we have no plans at this time to enhance gfs_edit.
+
+.SH SEE ALSO
+gfs2_edit(8)


