1jfs_debugfs(8) JFS file system editor jfs_debugfs(8)
2
8 jfs_debugfs - shell-type JFS file system editor
9
12 jfs_debugfs device
13
16 jfs_debugfs is a program which can be used to perform various low-level
17 actions on a JFS formatted device.
18 device is the special file name corresponding to the actual device to
20 be edited (e.g. /dev/hdb1).
21 jfs_debugfs must be run as root.
23
26 a[lter] <block> <offset> <hex_string>
27 replaces the data located at the <offset> of <block> with
28 <hex_string>
29 <block> is the block number - given in decimal
31 <offset> is the offset within that block - given in hexadecimal
33 <hex_string> is an even-numbered string of hexadecimal digits to
35 write to the disk
36 b[tree] <block> [<offset>]
39 * not implemented yet *
40 displays one node of the btree located at <offset> of <block>
41 and enters a subcommand mode to navigate the btree
42 SUBCOMMANDS:
44 l => visit left sibling
45 m => modify current node
46 p => visit parent node
47 r => visit right sibling
48 [0-9] => visit the n'th child node
49 x => exit subcommand mode
50 cb[blfsck]
53 displays the area used by ClearBadBlockList for communication
54 with fsck
55 SUBCOMMANDS:
57 m => modify entries
58 x => exit subcommand mode
59 dir[ectory] <inode_number> [<file_set>]
62 displays the directory entries at <inode_number> and enters
63 subcommand mode
64 <inode_number> is the directory's inode - given in decimal
66 <file_set> currently must be zero
68 SUBCOMMANDS:
70 m => modify entries
71 x => exit subcommand mode
72 d[isplay] [<block> [<offset> [<format> [<count>]]]]
75 displays <count> objects located at the <offset> of <block> in
76 <format>
77 <block> is the block number - given in decimal
79 <offset> is the offset within <block> - given in hexadecimal
81 <format> is one of the following:
83 a => ascii
84 b => block allocation map
85 d => decimal
86 i => inode
87 I => inode allocation map
88 s => superblock
89 x => hexadecimal
90 X => extent allocation descriptor
91 <count> is the number of objects to display - given in decimal
93 dm[ap]
96 displays aggregate disk (block) map
97 SUBCOMMANDS
99 m => modify map fields
100 f => display free count
101 t => display tree levels
102 x => exit subcommand mode
103 dt[ree] <inode_number> [<file_set>]
106 displays root of the directory btree located at <inode_number>
107 and enters a subcommand mode to navigate the btree
108 <inode_number> is the directory's inode - given in decimal
110 <file_set> currently must be zero
112 SUBCOMMANDS
114 l => visit left sibling
115 m => modify current node
116 p => visit parent node (not parent directory)
117 r => visit right sibling
118 [0-9] => visit the n'th child node
119 x => exit subcommand mode
120 fsckw[sphdr]
123 displays the header of the fsck workspace in the aggregate
124 SUBCOMMANDS:
126 m => modify entries
127 x => exit subcommand mode
128 h[elp] [<command>]
131 displays help for <command>
132 if no command is given, all possible commands are displayed
133 ia[g] [<IAG_number>] [a | s | <file_set>]
136 displays IAG information for <IAG_number> and enters subcommand
137 mode
138 <IAG_number> is given in decimal
140 a is to use the primary aggregate inode table
142 s is to use the secondary aggregate inode table
144 <file_set> currently must be zero
146 SUBCOMMANDS
148 e => display/modify inode extents map
149 m => modify IAG
150 p => display/modify persistent map
151 w => display/modify working map
152 x => exit subcommand mode
153 i[node] [<inode_number>] [a | s | <file_set>]
156 displays inode information for <inode_number> and enters sub‐
157 command mode
158 <inode_number> is given in decimal
160 a is to use the primary aggregate inode table
162 s is to use the secondary aggregate inode table
164 <file_set> currently must be zero
166 SUBCOMMANDS
168 a => display/modify inode's ACL
169 m => modify inode
170 x => exit subcommand mode
171 logs[uper]
174 displays the journal log superblock and enters subcommand mode
175 SUBCOMMANDS
177 m => modify journal log superblock
178 x => exit subcommand mode
179 q[uit]
182 exits jfs_debugfs
183 se[t] [<variable> <value>]
186 * not implemented yet *
187 set user-defined <variable> to <value>
188 if no arguments are given, displays all set variables
189 <variable> must begin with an alphabetic character
191 su[perblock] [p | s]
194 displays superblock data
195 p displays the primary superblock
197 s displays the secondary superblock
199 SUBCOMMANDS:
201 m => modify entries
202 x => exit subcommand mode
203 s2p[erblock] [p | s]
206 displays alternate superblock data
207 p displays the primary superblock
209 s displays the secondary superblock
211 SUBCOMMANDS:
213 m => modify entries
214 x => exit subcommand mode
215 u[nset] <variable>
218 * not implemented yet *
219 deletes user-defined <variable>
220 xt[ree] <inode_number> [<file_set>]
223 displays root of the non-directory btree located at <inode_num‐
224 ber> and enters a subcommand mode to navigate the btree
225 <inode_number> is the directory's inode - given in decimal
227 <file_set> currently must be zero
229 SUBCOMMANDS
231 l => visit left sibling
232 m => modify current node
233 p => visit parent node (not parent directory)
234 r => visit right sibling
235 [0-9] => visit the n'th child node
236 x => exit subcommand mode
237
240 If you find a bug in JFS or jfs_debugfs, please report it via the bug
241 tracking system ("Report Bugs" section) of the JFS project web site:
242 http://jfs.sourceforge.net/
243 Please send as much pertinent information as possible, including the
245 complete output of running jfs_fsck with the -v and -n options on the
246 JFS device.
247
250 jfs_fsck(8), jfs_mkfs(8), jfs_fscklog(8), jfs_logdump(8), jfs_tune(8),
251
254 Barry Arndt (barndt@us.ibm.com)
255 William Braswell, Jr.
256 jfs_debugfs is maintained by IBM.
258 See the JFS project web site for more details:
259 http://jfs.sourceforge.net/
260 October 29, 2002 jfs_debugfs(8)