fsck_hfs/fsck_hfs.8

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  17 .\"     @(#)fsck_hfs.8
  18 .Dd August 5, 2008
  19 .Dt FSCK_HFS 8
  20 .Os "Mac OS X"
  21 .Sh NAME
  22 .Nm fsck_hfs
  23 .Nd HFS file system consistency check
  24 .Sh SYNOPSIS
  25 .Nm fsck_hfs
  26 .Fl q
  27 .Op Fl df
  28 .Ar special ...
  29 .Nm fsck_hfs
  30 .Fl p
  31 .Op Fl df
  32 .Ar special ...
  33 .Nm fsck_hfs
  34 .Op Fl n | y | r
  35 .Op Fl dfgxlES
  36 .Op Fl D Ar flags
  37 .Op Fl b Ar size
  38 .Op Fl B Ar path
  39 .Op Fl m Ar mode
  40 .Op Fl c Ar size
  41 .Op Fl R Ar flags
  42 .Ar special ...
  43 .Sh DESCRIPTION
  44 .Pp
  45 The
  46 .Nm
  47 utility verifies and repairs standard HFS and HFS+ file systems.
  48 .Pp
  49 The first form of
  50 .Nm
  51 quickly checks the specified file systems to determine whether
  52 they were cleanly unmounted.
  53 .Pp
  54 The second form of
  55 .Nm
  56 preens the specified file systems.
  57 It is normally started by
  58 .Xr fsck 8
  59 run from
  60 .Pa /etc/rc.boot
  61 during automatic reboot, when a HFS file system is detected.
  62 When preening file systems,
  63 .Nm
  64 will fix common inconsistencies for file systems that were not
  65 unmounted cleanly.
  66 If more serious problems are found,
  67 .Nm
  68 does not try to fix them, indicates that it was not
  69 successful, and exits.
  70 .Pp
  71 The third form of
  72 .Nm
  73 checks the specified file systems and tries to repair all
  74 detected inconsistencies.
  75 .Pp
  76 If no options are specified
  77 .Nm
  78 will always check and attempt to fix the specified file systems.
  79 .Pp
  80 The options are as follows:
  81 .Bl -hang -offset indent
  82 .It Fl c Ar size
  83 Specify the
  84 .Ar size
  85 of the cache used by
  86 .Nm
  87 internally.  Bigger
  88 .Ar size
  89 can result in better performance but can result in deadlock when
  90 used with
  91 .Fl l
  92 option.  Size can be specified as a decimal, octal, or
  93 hexadecimal number.  If the number ends with a ``k'', ``m'',
  94 or ``g'', the number is multiplied by 1024 (1K), 1048576 (1M),
  95 or 1073741824 (1G), respectively.
  96 .It Fl d
  97 Display debugging information.
  98 This option may provide useful information when
  99 .Nm
 100 cannot repair a damaged file system.
 101 .It Fl D Ar flags
 102 Print extra debugging information.  The
 103 .Ar flags
 104 are a bitmap that control which kind of debug information is printed.
 105 The following values are currently implemented:
 106 .Bl -hang -offset indent -compact
 107 .It 0x0001
 108 Informational messages
 109 .It 0x0002
 110 Error messages
 111 .It 0x0010
 112 Extended attributes related messages
 113 .It 0x0020
 114 Overlapped extents related messages
 115 .El
 116 .It Fl b Ar size
 117 Specify the size, in bytes, of the physical blocks used by the
 118 .Fl B
 119 option.
 120 .It Fl B Ar path
 121 Print the files containing the physical blocks listed in the file
 122 .Ar path .
 123 The file should contain one or more decimal, octal (with leading 0) or
 124 hexadecimal (with leading 0x) numbers separated by white space.  The physical
 125 block numbers are relative to the start of the partition, so if you
 126 have block numbers relative to the start of the device, you will have to
 127 subtract the block number of the start of the partition.  The size of a
 128 physical block is given with the
 129 .Fl b
 130 option; the default is 512 bytes per block.
 131 .It Fl f
 132 When used with the
 133 .Fl p
 134 option, force
 135 .Nm
 136 to check `clean' file systems, otherwise it means force
 137 .Nm
 138 to check and repair journaled HFS+ file systems.
 139 .It Fl g
 140 Causes
 141 .Nm
 142 to generate its output strings in GUI format.
 143 This option is used when another application with a graphical user interface
 144 (like Mac OS X Disk Utility) is invoking the
 145 .Nm
 146 tool.
 147 .It Fl x
 148 Causes
 149 .Nm
 150 to generate its output strings in XML (plist) format.  This option
 151 implies the
 152 .Fl g
 153 option.
 154 .It Fl l
 155 Lock down the file system and perform a test-only check.
 156 This makes it possible to check a file system that is currently mounted,
 157 although no repairs can be made.
 158 .It Fl m Ar mode
 159 Mode is an octal number that will be used to set the permissions for the
 160 lost+found directory when it is created.
 161 The lost+found directory is only created when a volume is repaired and orphaned
 162 files or directories are detected.
 163 .Nm
 164 places orphaned files and directories into the lost+found directory (located
 165 at the root of the volume).
 166 The default mode is 01777.
 167 .It Fl p
 168 Preen the specified file systems.
 169 .It Fl q
 170 Causes
 171 .Nm
 172 to quickly check whether the volume was unmounted cleanly.
 173 If the volume was unmounted cleanly, then the exit status is 0.
 174 If the volume was not unmounted cleanly, then the exit status will be non-zero.
 175 In either case, a message is printed to standard output describing whether the
 176 volume was clean or dirty.
 177 .It Fl y
 178 Always attempt to repair any damage that is found.
 179 .It Fl n
 180 Never attempt to repair any damage that is found.
 181 .It Fl E
 182 Cause
 183 .Nm
 184 to exit (with a value of 47) if it encounters any
 185 major errors.  A ``major error'' is considered one which
 186 would impact using the volume in normal usage; an inconsistency
 187 which would not impact such use is considered ``minor'' for this
 188 option.  Only valid with the
 189 .Fl n
 190 option.
 191 .It Fl S
 192 Cause
 193 .Nm
 194 to scan the entire device looking for I/O errors.  It will
 195 attempt to map the blocks with errors to names, similar to
 196 the
 197 .Fl B
 198 option.
 199 .It Fl R Ar flags
 200 Rebuilds the requested btree.  The following flags are supported:
 201 .Bl -hang -offset indent -compact
 202 .It a
 203 Attribute btree
 204 .It c
 205 Catalog btree
 206 .It e
 207 Extents overflow btree
 208 .El
 209 Rebuilding a btree will only
 210 work if there is enough free space on the file system for the new btree
 211 file, and if
 212 .Nm
 213 is able to traverse each of the nodes in the requested btree successfully.
 214 Rebuilding btrees is not supported on HFS Standard volumes.
 215 .It Fl r
 216 Rebuild the catalog btree.  This is synonymous with
 217 .Fl Rc .
 218 .El
 219 .Pp
 220 Because of inconsistencies between the block device and the buffer cache,
 221 the raw device should always be used.
 222 .Sh EXIT VALUES
 223 .Nm
 224 indicates some status by exit value.  The current list of exit status results
 225 is:
 226 .Bl -hang -offset indent -compact
 227 .It 0
 228 No errors found, or successfully repaired.
 229 .It 3
 230 A quick-check (the
 231 .Fl n
 232 option) found a dirty filesystem; no repairs were made.
 233 .It 4
 234 During boot, the root filesystem was found to be dirty; repairs were
 235 made, and the filesystem was remounted.  The system should be rebooted.
 236 .It 8
 237 A corrupt filesystem was found during a check, or repairs did not succeed.
 238 .It 47
 239 A major error was found with
 240 .Fl E .
 241 .El
 242 .Sh SEE ALSO
 243 .Xr fsck 8
 244 .Sh BUGS
 245 .Nm
 246 is not able to fix some inconsistencies that it detects.
 247 .Sh HISTORY
 248 The
 249 .Nm
 250 command appeared in Mac OS X Server 1.0 .