1jfs_debugfs(8) JFS file system editor jfs_debugfs(8)
2
6 jfs_debugfs - shell-type JFS file system editor
7
10 jfs_debugfs device
11
14 jfs_debugfs is a program which can be used to perform various low-level
15 actions on a JFS formatted device.
16 device is the special file name corresponding to the actual device to
18 be edited (e.g. /dev/hdb1).
19 jfs_debugfs must be run as root.
21
24 a[lter] <block> <offset> <hex_string>
25 replaces the data located at the <offset> of <block> with
26 <hex_string>
27 <block> is the block number - given in decimal
29 <offset> is the offset within that block - given in hexadecimal
31 <hex_string> is an even-numbered string of hexadecimal digits to
33 write to the disk
34 b[tree] <block> [<offset>]
37 * not implemented yet *
38 displays one node of the btree located at <offset> of <block>
39 and enters a subcommand mode to navigate the btree
40 SUBCOMMANDS:
42 l => visit left sibling
43 m => modify current node
44 p => visit parent node
45 r => visit right sibling
46 [0-9] => visit the n'th child node
47 x => exit subcommand mode
48 cb[blfsck]
51 displays the area used by ClearBadBlockList for communication
52 with fsck
53 SUBCOMMANDS:
55 m => modify entries
56 x => exit subcommand mode
57 dir[ectory] <inode_number> [<file_set>]
60 displays the directory entries at <inode_number> and enters
61 subcommand mode
62 <inode_number> is the directory's inode - given in decimal
64 <file_set> currently must be zero
66 SUBCOMMANDS:
68 m => modify entries
69 x => exit subcommand mode
70 d[isplay] [<block> [<offset> [<format> [<count>]]]]
73 displays <count> objects located at the <offset> of <block> in
74 <format>
75 <block> is the block number - given in decimal
77 <offset> is the offset within <block> - given in hexadecimal
79 <format> is one of the following:
81 a => ascii
82 b => block allocation map
83 d => decimal
84 i => inode
85 I => inode allocation map
86 s => superblock
87 x => hexadecimal
88 X => extent allocation descriptor
89 <count> is the number of objects to display - given in decimal
91 dm[ap]
94 displays aggregate disk (block) map
95 SUBCOMMANDS
97 m => modify map fields
98 f => display free count
99 t => display tree levels
100 x => exit subcommand mode
101 dt[ree] <inode_number> [<file_set>]
104 displays root of the directory btree located at <inode_number>
105 and enters a subcommand mode to navigate the btree
106 <inode_number> is the directory's inode - given in decimal
108 <file_set> currently must be zero
110 SUBCOMMANDS
112 l => visit left sibling
113 m => modify current node
114 p => visit parent node (not parent directory)
115 r => visit right sibling
116 [0-9] => visit the n'th child node
117 x => exit subcommand mode
118 fsckw[sphdr]
121 displays the header of the fsck workspace in the aggregate
122 SUBCOMMANDS:
124 m => modify entries
125 x => exit subcommand mode
126 h[elp] [<command>]
129 displays help for <command>
130 if no command is given, all possible commands are displayed
131 ia[g] [<IAG_number>] [a | s | <file_set>]
134 displays IAG information for <IAG_number> and enters subcommand
135 mode
136 <IAG_number> is given in decimal
138 a is to use the primary aggregate inode table
140 s is to use the secondary aggregate inode table
142 <file_set> currently must be zero
144 SUBCOMMANDS
146 e => display/modify inode extents map
147 m => modify IAG
148 p => display/modify persistent map
149 w => display/modify working map
150 x => exit subcommand mode
151 i[node] [<inode_number>] [a | s | <file_set>]
154 displays inode information for <inode_number> and enters sub‐
155 command mode
156 <inode_number> is given in decimal
158 a is to use the primary aggregate inode table
160 s is to use the secondary aggregate inode table
162 <file_set> currently must be zero
164 SUBCOMMANDS
166 a => display/modify inode's ACL
167 m => modify inode
168 x => exit subcommand mode
169 logs[uper]
172 displays the journal log superblock and enters subcommand mode
173 SUBCOMMANDS
175 m => modify journal log superblock
176 x => exit subcommand mode
177 q[uit]
180 exits jfs_debugfs
181 se[t] [<variable> <value>]
184 * not implemented yet *
185 set user-defined <variable> to <value>
186 if no arguments are given, displays all set variables
187 <variable> must begin with an alphabetic character
189 su[perblock] [p | s]
192 displays superblock data
193 p displays the primary superblock
195 s displays the secondary superblock
197 SUBCOMMANDS:
199 m => modify entries
200 x => exit subcommand mode
201 s2p[erblock] [p | s]
204 displays alternate superblock data
205 p displays the primary superblock
207 s displays the secondary superblock
209 SUBCOMMANDS:
211 m => modify entries
212 x => exit subcommand mode
213 u[nset] <variable>
216 * not implemented yet *
217 deletes user-defined <variable>
218 xt[ree] <inode_number> [<file_set>]
221 displays root of the non-directory btree located at <inode_num‐
222 ber> and enters a subcommand mode to navigate the btree
223 <inode_number> is the directory's inode - given in decimal
225 <file_set> currently must be zero
227 SUBCOMMANDS
229 l => visit left sibling
230 m => modify current node
231 p => visit parent node (not parent directory)
232 r => visit right sibling
233 [0-9] => visit the n'th child node
234 x => exit subcommand mode
235
238 If you find a bug in JFS or jfs_debugfs, please report it via the bug
239 tracking system ("Report Bugs" section) of the JFS project web site:
240 http://jfs.sourceforge.net/
241 Please send as much pertinent information as possible, including the
243 complete output of running jfs_fsck with the -v and -n options on the
244 JFS device.
245
248 jfs_fsck(8), jfs_mkfs(8), jfs_fscklog(8), jfs_logdump(8), jfs_tune(8),
249
252 Barry Arndt (barndt@us.ibm.com)
253 William Braswell, Jr.
254 jfs_debugfs is maintained by IBM.
256 See the JFS project web site for more details:
257 http://jfs.sourceforge.net/
258 October 29, 2002 jfs_debugfs(8)