1jfs_debugfs(8)              JFS file system editor              jfs_debugfs(8)
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NAME

6       jfs_debugfs - shell-type JFS file system editor
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SYNOPSIS

10       jfs_debugfs device
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DESCRIPTION

14       jfs_debugfs is a program which can be used to perform various low-level
15       actions on a JFS formatted device.
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17       device is the special file name corresponding to the actual  device  to
18       be edited (e.g. /dev/hdb1).
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20       jfs_debugfs must be run as root.
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COMMANDS

24       a[lter] <block> <offset> <hex_string>
25               replaces  the  data  located  at  the  <offset> of <block> with
26              <hex_string>
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28              <block> is the block number - given in decimal
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30              <offset> is the offset within that block - given in hexadecimal
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32              <hex_string> is an even-numbered string of hexadecimal digits to
33              write to the disk
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36       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
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41              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
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50       cb[blfsck]
51               displays the area used by ClearBadBlockList  for  communication
52              with fsck
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54              SUBCOMMANDS:
55               m => modify entries
56               x => exit subcommand mode
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58
59       dir[ectory] <inode_number> [<file_set>]
60               displays  the  directory  entries  at <inode_number> and enters
61              subcommand mode
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63              <inode_number> is the directory's inode - given in decimal
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65              <file_set> currently must be zero
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67              SUBCOMMANDS:
68               m => modify entries
69               x => exit subcommand mode
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72       d[isplay] [<block> [<offset> [<format> [<count>]]]]
73              displays <count> objects located at the <offset> of  <block>  in
74              <format>
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76              <block> is the block number - given in decimal
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78              <offset> is the offset within <block> - given in hexadecimal
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80              <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
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90              <count> is the number of objects to display - given in decimal
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93       dm[ap]
94               displays aggregate disk (block) map
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96              SUBCOMMANDS
97               m => modify map fields
98               f => display free count
99               t => display tree levels
100               x => exit subcommand mode
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102
103       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
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107              <inode_number> is the directory's inode - given in decimal
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109              <file_set> currently must be zero
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111              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
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120       fsckw[sphdr]
121               displays the header of the fsck workspace in the aggregate
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123              SUBCOMMANDS:
124               m => modify entries
125               x => exit subcommand mode
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127
128       h[elp] [<command>]
129               displays help for <command>
130               if no command is given, all possible commands are displayed
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132
133       ia[g] [<IAG_number>] [a | s | <file_set>]
134               displays IAG information for <IAG_number> and enters subcommand
135              mode
136
137              <IAG_number> is given in decimal
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139              a is to use the primary aggregate inode table
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141              s is to use the secondary aggregate inode table
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143              <file_set> currently must be zero
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145              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
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153       i[node] [<inode_number>] [a | s | <file_set>]
154               displays  inode  information for <inode_number> and enters sub‐
155              command mode
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157              <inode_number> is given in decimal
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159              a is to use the primary aggregate inode table
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161              s is to use the secondary aggregate inode table
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163              <file_set> currently must be zero
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165              SUBCOMMANDS
166               a => display/modify inode's ACL
167               m => modify inode
168               x => exit subcommand mode
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171       logs[uper]
172               displays the journal log superblock and enters subcommand mode
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174              SUBCOMMANDS
175               m => modify journal log superblock
176               x => exit subcommand mode
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178
179       q[uit]
180               exits jfs_debugfs
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182
183       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
188              <variable> must begin with an alphabetic character
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191       su[perblock] [p | s]
192               displays superblock data
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194              p displays the primary superblock
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196              s displays the secondary superblock
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198              SUBCOMMANDS:
199               m => modify entries
200               x => exit subcommand mode
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203       s2p[erblock] [p | s]
204               displays alternate superblock data
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206              p displays the primary superblock
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208              s displays the secondary superblock
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210              SUBCOMMANDS:
211               m => modify entries
212               x => exit subcommand mode
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214
215       u[nset] <variable>
216              * not implemented yet *
217               deletes user-defined <variable>
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220       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
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224              <inode_number> is the directory's inode - given in decimal
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226              <file_set> currently must be zero
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228              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
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REPORTING BUGS

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/
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242       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.
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SEE ALSO

248       jfs_fsck(8), jfs_mkfs(8), jfs_fscklog(8), jfs_logdump(8), jfs_tune(8),
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AUTHORS

252       Barry Arndt  (barndt@us.ibm.com)
253       William Braswell, Jr.
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255       jfs_debugfs is maintained by IBM.
256       See the JFS project web site for more details:
257       http://jfs.sourceforge.net/
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261                               October 29, 2002                 jfs_debugfs(8)
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