restore/restore.8

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  32 .\"     @(#)restore.8   8.4 (Berkeley) 5/1/95
  33 .\"
  34 .Dd May 1, 1995
  35 .Dt RESTORE 8
  36 .Os BSD 4
  37 .Sh NAME
  38 .Nm restore
  39 .Nd "restore files or file systems from backups made with dump"
  40 .Sh SYNOPSIS
  41 .Nm restore
  42 .Fl C
  43 .Op Fl cvy
  44 .Op Fl b Ar blocksize
  45 .Op Fl D Ar filesystem
  46 .Op Fl f Ar file
  47 .Op Fl s Ar fileno
  48 .Op Fl T Ar directory
  49 .Nm restore
  50 .Fl i
  51 .Op Fl chmNvy
  52 .Op Fl b Ar blocksize
  53 .Op Fl f Ar file
  54 .Op Fl s Ar fileno
  55 .Op Fl T Ar directory
  56 .Nm restore
  57 .Fl R
  58 .Op Fl cNvy
  59 .Op Fl b Ar blocksize
  60 .Op Fl f Ar file
  61 .Op Fl s Ar fileno
  62 .Op Fl T Ar directory
  63 .Nm restore
  64 .Fl r
  65 .Op Fl cNvy
  66 .Op Fl b Ar blocksize
  67 .Op Fl f Ar file
  68 .Op Fl s Ar fileno
  69 .Op Fl T Ar directory
  70 .Nm restore
  71 .Fl t
  72 .Op Fl chvy
  73 .Op Fl b Ar blocksize
  74 .Op Fl f Ar file
  75 .Op Fl s Ar fileno
  76 .Op Fl T Ar directory
  77 .Op file ...
  78 .Nm restore
  79 .Fl x
  80 .Op Fl chmNvy
  81 .Op Fl b Ar blocksize
  82 .Op Fl f Ar file
  83 .Op Fl s Ar fileno
  84 .Op Fl T Ar directory
  85 .Op file ...
  86 .Pp
  87 .in -\\n(iSu
  88 (The
  89 .Bx 4.3
  90 option syntax is implemented for backward compatibility, but
  91 is not documented here.)
  92 .Sh DESCRIPTION
  93 The
  94 .Nm restore
  95 command performs the inverse function of
  96 .Xr dump 8 .
  97 A full backup of a file system may be restored and
  98 subsequent incremental backups layered on top of it.
  99 Single files and
 100 directory subtrees may be restored from full or partial
 101 backups.
 102 .Nm Restore
 103 works across a network;
 104 to do this see the
 105 .Fl f
 106 flag described below.
 107 Other arguments to the command are file or directory
 108 names specifying the files that are to be restored.
 109 Unless the
 110 .Fl h
 111 flag is specified (see below),
 112 the appearance of a directory name refers to
 113 the files and (recursively) subdirectories of that directory.
 114 .Pp
 115 Exactly one of the following flags is required:
 116 .Bl -tag -width Ds
 117 .It Fl C
 118 This mode allows comparison of files from a dump.
 119 .Nm Restore
 120 reads the backup and compares its contents with files present on the
 121 disk.
 122 It first changes its working directory to the root of the filesystem
 123 that was dumped and compares the tape with the files in its new
 124 current directory.
 125 .It Fl i
 126 This mode allows interactive restoration of files from a dump.
 127 After reading in the directory information from the dump,
 128 .Nm restore
 129 provides a shell like interface that allows the user to move
 130 around the directory tree selecting files to be extracted.
 131 The available commands are given below;
 132 for those commands that require an argument,
 133 the default is the current directory.
 134 .Bl -tag -width Fl
 135 .It Ic add Op Ar arg
 136 The current directory or specified argument is added to the list of
 137 files to be extracted.
 138 If a directory is specified, then it and all its descendents are
 139 added to the extraction list
 140 (unless the
 141 .Fl h
 142 flag is specified on the command line).
 143 Files that are on the extraction list are prepended with a ``*''
 144 when they are listed by
 145 .Ic ls .
 146 .It Ic \&cd Ar arg
 147 Change the current working directory to the specified argument.
 148 .It Ic delete Op Ar arg
 149 The current directory or specified argument is deleted from the list of
 150 files to be extracted.
 151 If a directory is specified, then it and all its descendents are
 152 deleted from the extraction list
 153 (unless the
 154 .Fl h
 155 flag is specified on the command line).
 156 The most expedient way to extract most of the files from a directory
 157 is to add the directory to the extraction list and then delete
 158 those files that are not needed.
 159 .It Ic extract
 160 All the files that are on the extraction list are extracted
 161 from the dump.
 162 .Nm Restore
 163 will ask which volume the user wishes to mount.
 164 The fastest way to extract a few files is to
 165 start with the last volume, and work towards the first volume.
 166 .It Ic help
 167 List a summary of the available commands.
 168 .It Ic \&ls Op Ar arg
 169 List the current or specified directory.
 170 Entries that are directories are appended with a ``/''.
 171 Entries that have been marked for extraction are prepended with a ``*''.
 172 If the verbose
 173 flag is set the inode number of each entry is also listed.
 174 .It Ic pwd
 175 Print the full pathname of the current working directory.
 176 .It Ic quit
 177 Restore immediately exits,
 178 even if the extraction list is not empty.
 179 .It Ic setmodes
 180 All the directories that have been added to the extraction list
 181 have their owner, modes, and times set;
 182 nothing is extracted from the dump.
 183 This is useful for cleaning up after a restore has been prematurely aborted.
 184 .It Ic verbose
 185 The sense of the
 186 .Fl v
 187 flag is toggled.
 188 When set, the verbose flag causes the
 189 .Ic ls
 190 command to list the inode numbers of all entries.
 191 It also causes
 192 .Nm restore
 193 to print out information about each file as it is extracted.
 194 .El
 195 .It Fl R
 196 .Nm Restore
 197 requests a particular tape of a multi volume set on which to restart
 198 a full restore
 199 (see the
 200 .Fl r
 201 flag below).
 202 This is useful if the restore has been interrupted.
 203 .It Fl r
 204 Restore (rebuild a file system).
 205 The target file system should be made pristine with
 206 .Xr newfs 8 ,
 207 mounted and the user
 208 .Xr cd Ns 'd
 209 into the pristine file system
 210 before starting the restoration of the initial level 0 backup. If the
 211 level 0 restores successfully, the
 212 .Fl r
 213 flag may be used to restore
 214 any necessary incremental backups on top of the level 0.
 215 The
 216 .Fl r
 217 flag precludes an interactive file extraction and can be
 218 detrimental to one's health if not used carefully (not to mention
 219 the disk). An example:
 220 .Bd -literal -offset indent
 221 newfs /dev/rrp0g eagle
 222 mount /dev/rp0g /mnt
 223 cd /mnt
 224
 225 restore rf /dev/rst8
 226 .Ed
 227 .Pp
 228 Note that
 229 .Nm restore
 230 leaves a file
 231 .Pa restoresymtable
 232 in the root directory to pass information between incremental
 233 restore passes.
 234 This file should be removed when the last incremental has been
 235 restored.
 236 .Pp
 237 .Nm Restore ,
 238 in conjunction with
 239 .Xr newfs 8
 240 and
 241 .Xr dump 8 ,
 242 may be used to modify file system parameters
 243 such as size or block size.
 244 .It Fl t
 245 The names of the specified files are listed if they occur
 246 on the backup.
 247 If no file argument is given,
 248 then the root directory is listed,
 249 which results in the entire content of the
 250 backup being listed,
 251 unless the
 252 .Fl h
 253 flag has been specified.
 254 Note that the
 255 .Fl t
 256 flag replaces the function of the old
 257 .Xr dumpdir 8
 258 program.
 259 .ne 1i
 260 .It Fl x
 261 The named files are read from the given media.
 262 If a named file matches a directory whose contents
 263 are on the backup
 264 and the
 265 .Fl h
 266 flag is not specified,
 267 the directory is recursively extracted.
 268 The owner, modification time,
 269 and mode are restored (if possible).
 270 If no file argument is given,
 271 then the root directory is extracted,
 272 which results in the entire content of the
 273 backup being extracted,
 274 unless the
 275 .Fl h
 276 flag has been specified.
 277 .El
 278 .Pp
 279 The following additional options may be specified:
 280 .Bl -tag -width Ds
 281 .It Fl b Ar blocksize
 282 The number of kilobytes per dump record.
 283 If the
 284 .Fl b
 285 option is not specified,
 286 .Nm restore
 287 tries to determine the block size dynamically.
 288 .It Fl c
 289 Normally,
 290 .Nm restore
 291 will try to determine dynamically whether the dump was made from an
 292 old (pre-4.4) or new format file sytem.  The
 293 .Fl c
 294 flag disables this check, and only allows reading a dump in the old
 295 format.
 296 .It Fl D Ar filesystem
 297 The
 298 .Fl D
 299 flag allows the user to specify the filesystem name when using
 300 .Nm restore
 301 with the
 302 .Fl C
 303 option to check the backup.
 304 .It Fl f Ar file
 305 Read the backup from
 306 .Ar file ;
 307 .Ar file
 308 may be a special device file
 309 like
 310 .Pa /dev/rmt12
 311 (a tape drive),
 312 .Pa /dev/rsd1c
 313 (a disk drive),
 314 an ordinary file,
 315 or
 316 .Ql Fl
 317 (the standard input).
 318 If the name of the file is of the form
 319 .Dq host:file ,
 320 or
 321 .Dq user@host:file ,
 322 .Nm restore
 323 reads from the named file on the remote host using
 324 .Xr rmt 8 .
 325 .Pp
 326 .It Fl h
 327 Extract the actual directory,
 328 rather than the files that it references.
 329 This prevents hierarchical restoration of complete subtrees
 330 from the dump.
 331 .It Fl m
 332 Extract by inode numbers rather than by file name.
 333 This is useful if only a few files are being extracted,
 334 and one wants to avoid regenerating the complete pathname
 335 to the file.
 336 .It Fl N
 337 The
 338 .Fl N
 339 flag causes
 340 .Nm restore to only print file names. Files are not extracted.
 341 .It Fl s Ar fileno
 342 Read from the specified
 343 .Ar fileno
 344 on a multi-file tape.
 345 File numbering starts at 1.
 346 .It Fl T Ar directory
 347 The
 348 .Fl T
 349 flag allows the user to specify a directory to use for the storage of
 350 temporary files. The default value is /tmp. This flag is most useful
 351 when restoring files after having booted from a floppy.  There might be little
 352 or no space on the floppy filesystem, but another source of space might exist.
 353 .It Fl v
 354 Normally
 355 .Nm restore
 356 does its work silently.
 357 The
 358 .Fl v
 359 (verbose)
 360 flag causes it to type the name of each file it treats
 361 preceded by its file type.
 362 .It Fl y
 363 Do not ask the user whether to abort the restore in the event of an error.
 364 Always try to skip over the bad block(s) and continue.
 365 .El
 366 .Sh DIAGNOSTICS
 367 Complaints if it gets a read error.
 368 If
 369 .Fl y
 370 has been specified, or the user responds
 371 .Ql y ,
 372 .Nm restore
 373 will attempt to continue the restore.
 374 .Pp
 375 If a backup was made using more than one tape volume,
 376 .Nm restore
 377 will notify the user when it is time to mount the next volume.
 378 If the
 379 .Fl x
 380 or
 381 .Fl i
 382 flag has been specified,
 383 .Nm restore
 384 will also ask which volume the user wishes to mount.
 385 The fastest way to extract a few files is to
 386 start with the last volume, and work towards the first volume.
 387 .Pp
 388 There are numerous consistency checks that can be listed by
 389 .Nm restore .
 390 Most checks are self-explanatory or can ``never happen''.
 391 Common errors are given below.
 392 .Pp
 393 .Bl -tag -width Ds -compact
 394 .It Converting to new file system format.
 395 A dump tape created from the old file system has been loaded.
 396 It is automatically converted to the new file system format.
 397 .Pp
 398 .It <filename>: not found on tape
 399 The specified file name was listed in the tape directory,
 400 but was not found on the tape.
 401 This is caused by tape read errors while looking for the file,
 402 and from using a dump tape created on an active file system.
 403 .Pp
 404 .It expected next file <inumber>, got <inumber>
 405 A file that was not listed in the directory showed up.
 406 This can occur when using a dump created on an active file system.
 407 .Pp
 408 .It Incremental dump too low
 409 When doing incremental restore,
 410 a dump that was written before the previous incremental dump,
 411 or that has too low an incremental level has been loaded.
 412 .Pp
 413 .It Incremental dump too high
 414 When doing incremental restore,
 415 a dump that does not begin its coverage where the previous incremental
 416 dump left off,
 417 or that has too high an incremental level has been loaded.
 418 .Pp
 419 .It Tape read error while restoring <filename>
 420 .It Tape read error while skipping over inode <inumber>
 421 .It Tape read error while trying to resynchronize
 422 A tape (or other media) read error has occurred.
 423 If a file name is specified,
 424 then its contents are probably partially wrong.
 425 If an inode is being skipped or the tape is trying to resynchronize,
 426 then no extracted files have been corrupted,
 427 though files may not be found on the tape.
 428 .Pp
 429 .It resync restore, skipped <num> blocks
 430 After a dump read error,
 431 .Nm restore
 432 may have to resynchronize itself.
 433 This message lists the number of blocks that were skipped over.
 434 .El
 435 .Sh FILES
 436 .Bl -tag -width "./restoresymtable" -compact
 437 .It Pa /dev/rmt?
 438 the default tape drive
 439 .It Pa /tmp/rstdir*
 440 file containing directories on the tape.
 441 .It Pa /tmp/rstmode*
 442 owner, mode, and time stamps for directories.
 443 .It Pa \&./restoresymtable
 444 information passed between incremental restores.
 445 .El
 446 .Sh SEE ALSO
 447 .Xr dump 8 ,
 448 .Xr newfs 8 ,
 449 .Xr mount 8 ,
 450 .Xr mkfs 8 ,
 451 .Xr rmt 8
 452 .Sh BUGS
 453 .Nm Restore
 454 can get confused when doing incremental restores from
 455 dumps that were made on active file systems.
 456 .Pp
 457 A level zero dump must be done after a full restore.
 458 Because restore runs in user code,
 459 it has no control over inode allocation;
 460 thus a full dump must be done to get a new set of directories
 461 reflecting the new inode numbering,
 462 even though the contents of the files is unchanged.
 463 .Sh HISTORY
 464 The
 465 .Nm restore
 466 command appeared in
 467 .Bx 4.2 .