restore/restore.8.in

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  32 .\"     @(#)restore.8   8.4 (Berkeley) 5/1/95
  33 .\"     $Id: restore.8.in,v 1.1 1999/10/11 13:08:09 stelian Exp $
  34 .\"
  35 .Dd __DATE__
  36 .Dt RESTORE 8
  37 .Os "__VERSION__"
  38 .Sh NAME
  39 .Nm restore
  40 .Nd "restore files or file systems from backups made with dump"
  41 .Sh SYNOPSIS
  42 .Nm restore
  43 .Fl C
  44 .Op Fl ckvy
  45 .Op Fl b Ar blocksize
  46 .Op Fl D Ar filesystem
  47 .Op Fl f Ar file
  48 .Op Fl s Ar fileno
  49 .Op Fl T Ar directory
  50 .Nm restore
  51 .Fl i
  52 .Op Fl chkmNuvy
  53 .Op Fl b Ar blocksize
  54 .Op Fl f Ar file
  55 .Op Fl s Ar fileno
  56 .Op Fl T Ar directory
  57 .Nm restore
  58 .Fl R
  59 .Op Fl ckNuvy
  60 .Op Fl b Ar blocksize
  61 .Op Fl f Ar file
  62 .Op Fl s Ar fileno
  63 .Op Fl T Ar directory
  64 .Nm restore
  65 .Fl r
  66 .Op Fl ckNuvy
  67 .Op Fl b Ar blocksize
  68 .Op Fl f Ar file
  69 .Op Fl s Ar fileno
  70 .Op Fl T Ar directory
  71 .Nm restore
  72 .Fl t
  73 .Op Fl chkNuvy
  74 .Op Fl b Ar blocksize
  75 .Op Fl f Ar file
  76 .Op Fl s Ar fileno
  77 .Op Fl T Ar directory
  78 .Op file ...
  79 .Nm restore
  80 .Fl x
  81 .Op Fl chkmNuvy
  82 .Op Fl b Ar blocksize
  83 .Op Fl f Ar file
  84 .Op Fl s Ar fileno
  85 .Op Fl T Ar directory
  86 .Op file ...
  87 .Pp
  88 .in
  89 (The
  90 .Bx 4.3
  91 option syntax is implemented for backward compatibility but
  92 is not documented here.)
  93 .Sh DESCRIPTION
  94 The
  95 .Nm restore
  96 command performs the inverse function of
  97 .Xr dump 8 .
  98 A full backup of a file system may be restored and
  99 subsequent incremental backups layered on top of it.
 100 Single files and
 101 directory subtrees may be restored from full or partial
 102 backups.
 103 .Nm Restore
 104 works across a network;
 105 to do this see the
 106 .Fl f
 107 flag described below.
 108 Other arguments to the command are file or directory
 109 names specifying the files that are to be restored.
 110 Unless the
 111 .Fl h
 112 flag is specified (see below),
 113 the appearance of a directory name refers to
 114 the files and (recursively) subdirectories of that directory.
 115 .Pp
 116 Exactly one of the following flags is required:
 117 .Bl -tag -width Ds
 118 .It Fl C
 119 This mode allows comparison of files from a dump.
 120 .Nm Restore
 121 reads the backup and compares its contents with files present on the
 122 disk.
 123 It first changes its working directory to the root of the filesystem
 124 that was dumped and compares the tape with the files in its new
 125 current directory.
 126 .It Fl i
 127 This mode allows interactive restoration of files from a dump.
 128 After reading in the directory information from the dump,
 129 .Nm restore
 130 provides a shell like interface that allows the user to move
 131 around the directory tree selecting files to be extracted.
 132 The available commands are given below;
 133 for those commands that require an argument,
 134 the default is the current directory.
 135 .Bl -tag -width Fl
 136 .It Ic add Op Ar arg
 137 The current directory or specified argument is added to the list of
 138 files to be extracted.
 139 If a directory is specified, then it and all its descendents are
 140 added to the extraction list
 141 (unless the
 142 .Fl h
 143 flag is specified on the command line).
 144 Files that are on the extraction list are prepended with a
 145 .Dq \&*
 146 when they are listed by
 147 .Ic ls .
 148 .It Ic \&cd Ar arg
 149 Change the current working directory to the specified argument.
 150 .It Ic delete Op Ar arg
 151 The current directory or specified argument is deleted from the list of
 152 files to be extracted.
 153 If a directory is specified, then it and all its descendents are
 154 deleted from the extraction list
 155 (unless the
 156 .Fl h
 157 flag is specified on the command line).
 158 The most expedient way to extract most of the files from a directory
 159 is to add the directory to the extraction list and then delete
 160 those files that are not needed.
 161 .It Ic extract
 162 All files on the extraction list are extracted
 163 from the dump.
 164 .Nm Restore
 165 will ask which volume the user wishes to mount.
 166 The fastest way to extract a few files is to
 167 start with the last volume and work towards the first volume.
 168 .It Ic help
 169 List a summary of the available commands.
 170 .It Ic \&ls Op Ar arg
 171 List the current or specified directory.
 172 Entries that are directories are appended with a
 173 .Dq \&* .
 174 Entries that have been marked for extraction are prepended with a ``*''.
 175 If the verbose
 176 flag is set, the inode number of each entry is also listed.
 177 .It Ic pwd
 178 Print the full pathname of the current working directory.
 179 .It Ic quit
 180 Restore immediately exits,
 181 even if the extraction list is not empty.
 182 .It Ic setmodes
 183 All directories that have been added to the extraction list
 184 have their owner, modes, and times set;
 185 nothing is extracted from the dump.
 186 This is useful for cleaning up after a restore has been prematurely aborted.
 187 .It Ic verbose
 188 The sense of the
 189 .Fl v
 190 flag is toggled.
 191 When set, the verbose flag causes the
 192 .Ic ls
 193 command to list the inode numbers of all entries.
 194 It also causes
 195 .Nm restore
 196 to print out information about each file as it is extracted.
 197 .El
 198 .It Fl R
 199 .Nm Restore
 200 requests a particular tape of a multi-volume set on which to restart
 201 a full restore
 202 (see the
 203 .Fl r
 204 flag below).
 205 This is useful if the restore has been interrupted.
 206 .It Fl r
 207 Restore (rebuild) a file system.
 208 The target file system should be made pristine with
 209 .Xr mke2fs 8 ,
 210 mounted, and the user
 211 .Xr cd Ns 'd
 212 into the pristine file system
 213 before starting the restoration of the initial level 0 backup. If the
 214 level 0 restores successfully, the
 215 .Fl r
 216 flag may be used to restore
 217 any necessary incremental backups on top of the level 0.
 218 The
 219 .Fl r
 220 flag precludes an interactive file extraction and can be
 221 detrimental to one's health (not to mention the disk) if not used carefully.
 222 An example:
 223 .Bd -literal -offset indent
 224 mke2fs /dev/sda1
 225 mount /dev/sda1 /mnt
 226 cd /mnt
 227
 228 restore rf /dev/st0
 229 .Ed
 230 .Pp
 231 Note that
 232 .Nm restore
 233 leaves a file
 234 .Pa restoresymtable
 235 in the root directory to pass information between incremental
 236 restore passes.
 237 This file should be removed when the last incremental has been
 238 restored.
 239 .Pp
 240 .Nm Restore ,
 241 in conjunction with
 242 .Xr mke2fs 8
 243 and
 244 .Xr dump 8 ,
 245 may be used to modify file system parameters
 246 such as size or block size.
 247 .It Fl t
 248 The names of the specified files are listed if they occur
 249 on the backup.
 250 If no file argument is given,
 251 the root directory is listed,
 252 which results in the entire content of the
 253 backup being listed,
 254 unless the
 255 .Fl h
 256 flag has been specified.
 257 Note that the
 258 .Fl t
 259 flag replaces the function of the old
 260 .Xr dumpdir 8
 261 program.
 262 .ne 1i
 263 .It Fl x
 264 The named files are read from the given media.
 265 If a named file matches a directory whose contents
 266 are on the backup
 267 and the
 268 .Fl h
 269 flag is not specified,
 270 the directory is recursively extracted.
 271 The owner, modification time,
 272 and mode are restored (if possible).
 273 If no file argument is given,
 274 the root directory is extracted,
 275 which results in the entire content of the
 276 backup being extracted,
 277 unless the
 278 .Fl h
 279 flag has been specified.
 280 .El
 281 .Pp
 282 The following additional options may be specified:
 283 .Bl -tag -width Ds
 284 .It Fl b Ar blocksize
 285 The number of kilobytes per dump record.
 286 If the
 287 .Fl b
 288 option is not specified,
 289 .Nm restore
 290 tries to determine the media block size dynamically.
 291 .It Fl c
 292 Normally,
 293 .Nm restore
 294 will try to determine dynamically whether the dump was made from an
 295 old (pre-4.4) or new format file system.  The
 296 .Fl c
 297 flag disables this check, and only allows reading a dump in the old
 298 format.
 299 .It Fl D Ar filesystem
 300 The
 301 .Fl D
 302 flag allows the user to specify the filesystem name when using
 303 .Nm restore
 304 with the
 305 .Fl C
 306 option to check the backup.
 307 .It Fl f Ar file
 308 Read the backup from
 309 .Ar file ;
 310 .Ar file
 311 may be a special device file
 312 like
 313 .Pa /dev/st0
 314 (a tape drive),
 315 .Pa /dev/sda1
 316 (a disk drive),
 317 an ordinary file,
 318 or
 319 .Ql Fl
 320 (the standard input).
 321 If the name of the file is of the form
 322 .Dq host:file
 323 or
 324 .Dq user@host:file ,
 325 .Nm restore
 326 reads from the named file on the remote host using
 327 .Xr rmt 8 .
 328 .Pp
 329 .It Fl k
 330 Use Kerberos authentication when contacting the remote tape server.
 331 (Only available if this options was enabled when
 332 .Nm restore
 333 was compiled.)
 334 .Pp
 335 .It Fl h
 336 Extract the actual directory,
 337 rather than the files that it references.
 338 This prevents hierarchical restoration of complete subtrees
 339 from the dump.
 340 .It Fl m
 341 Extract by inode numbers rather than by file name.
 342 This is useful if only a few files are being extracted,
 343 and one wants to avoid regenerating the complete pathname
 344 to the file.
 345 .It Fl N
 346 The
 347 .Fl N
 348 flag causes
 349 .Nm restore to only print file names. Files are not extracted.
 350 .It Fl s Ar fileno
 351 Read from the specified
 352 .Ar fileno
 353 on a multi-file tape.
 354 File numbering starts at 1.
 355 .It Fl T Ar directory
 356 The
 357 .Fl T
 358 flag allows the user to specify a directory to use for the storage of
 359 temporary files. The default value is /tmp. This flag is most useful
 360 when restoring files after having booted from a floppy.  There might be little
 361 or no space on the floppy filesystem, but another source of space might exist.
 362 .It Fl u
 363 When creating certain types of files, restore may generate a warning
 364 diagnostic if they already exist in the target directory.
 365 To prevent this, the
 366 .Fl u
 367 (unlink) flag causes restore to remove old entries before attempting
 368 to create new ones.
 369 .It Fl v
 370 Normally
 371 .Nm restore
 372 does its work silently.
 373 The
 374 .Fl v
 375 (verbose)
 376 flag causes it to type the name of each file it treats
 377 preceded by its file type.
 378 .It Fl y
 379 Do not ask the user whether to abort the restore in the event of an error.
 380 Always try to skip over the bad block(s) and continue.
 381 .El
 382 .Sh DIAGNOSTICS
 383 Complains if it gets a read error.
 384 If
 385 .Fl y
 386 has been specified, or the user responds
 387 .Ql y ,
 388 .Nm restore
 389 will attempt to continue the restore.
 390 .Pp
 391 If a backup was made using more than one tape volume,
 392 .Nm restore
 393 will notify the user when it is time to mount the next volume.
 394 If the
 395 .Fl x
 396 or
 397 .Fl i
 398 flag has been specified,
 399 .Nm restore
 400 will also ask which volume the user wishes to mount.
 401 The fastest way to extract a few files is to
 402 start with the last volume, and work towards the first volume.
 403 .Pp
 404 There are numerous consistency checks that can be listed by
 405 .Nm restore .
 406 Most checks are self-explanatory or can
 407 .Dq never happen .
 408 Common errors are given below.
 409 .Pp
 410 .Bl -tag -width Ds -compact
 411 .It Converting to new file system format
 412 A dump tape created from the old file system has been loaded.
 413 It is automatically converted to the new file system format.
 414 .Pp
 415 .It <filename>: not found on tape
 416 The specified file name was listed in the tape directory,
 417 but was not found on the tape.
 418 This is caused by tape read errors while looking for the file,
 419 and from using a dump tape created on an active file system.
 420 .Pp
 421 .It expected next file <inumber>, got <inumber>
 422 A file that was not listed in the directory showed up.
 423 This can occur when using a dump created on an active file system.
 424 .Pp
 425 .It Incremental dump too low
 426 When doing an incremental restore,
 427 a dump that was written before the previous incremental dump,
 428 or that has too low an incremental level has been loaded.
 429 .Pp
 430 .It Incremental dump too high
 431 When doing an incremental restore,
 432 a dump that does not begin its coverage where the previous incremental
 433 dump left off,
 434 or that has too high an incremental level has been loaded.
 435 .Pp
 436 .It Tape read error while restoring <filename>
 437 .It Tape read error while skipping over inode <inumber>
 438 .It Tape read error while trying to resynchronize
 439 A tape (or other media) read error has occurred.
 440 If a file name is specified,
 441 its contents are probably partially wrong.
 442 If an inode is being skipped or the tape is trying to resynchronize,
 443 no extracted files have been corrupted,
 444 though files may not be found on the tape.
 445 .Pp
 446 .It resync restore, skipped <num> blocks
 447 After a dump read error,
 448 .Nm restore
 449 may have to resynchronize itself.
 450 This message lists the number of blocks that were skipped over.
 451 .El
 452 .Sh ENVIRONMENT
 453 If the following environment variable exists it will be utilized by
 454 .Nm restore :
 455 .Pp
 456 .Bl -tag -width "TMPDIR" -compact
 457 .It Ev TAPE
 458 If no -f option was specified,
 459 .Nm
 460 will use the device specified via
 461 .Ev TAPE
 462 as the dump device.
 463 .Ev TAPE
 464 may be of the form
 465 .Qq tapename ,
 466 .Qq host:tapename
 467 or
 468 .Qq user@host:tapename .
 469 .It Ev TMPDIR
 470 The directory given in
 471 .Ev TMPDIR
 472 will be used
 473 instead of
 474 .Pa /tmp
 475 to store temporary files.
 476 .It Ev RMT
 477 The environment variable
 478 .Ev RMT
 479 will be used to determine the pathname of the remote
 480 .Xr rmt 8
 481 program.
 482 .Sh FILES
 483 .Bl -tag -width "./restoresymtable" -compact
 484 .It Pa /dev/st0
 485 the default tape drive
 486 .It Pa /tmp/rstdir*
 487 file containing directories on the tape
 488 .It Pa /tmp/rstmode*
 489 owner, mode, and time stamps for directories
 490 .It Pa \&./restoresymtable
 491 information passed between incremental restores
 492 .El
 493 .Sh SEE ALSO
 494 .Xr dump 8 ,
 495 .Xr mount 8 ,
 496 .Xr mke2fs 8 ,
 497 .Xr rmt 8
 498 .Sh BUGS
 499 .Nm Restore
 500 can get confused when doing incremental restores from
 501 dumps that were made on active file systems.
 502 .Pp
 503 A level 0 dump must be done after a full restore.
 504 Because
 505 .Nm restore
 506 runs in user code,
 507 it has no control over inode allocation;
 508 thus a full dump must be done to get a new set of directories
 509 reflecting the new inode numbering,
 510 even though the content of the files is unchanged.
 511 .Pp
 512 The temporary files
 513 .Pa /tmp/rstdir*
 514 and
 515 .Pa /tmp/rstmode*
 516 are generated with a unique name based on the date of the dump
 517 and the process ID (see
 518 .Xr mktemp 3 ),
 519 except when
 520 .Fl r
 521 or
 522 .Fl R
 523 is used.
 524 Because
 525 .Fl R
 526 allows you to restart a
 527 .Fl r
 528 operation that may have been interrupted, the temporary files should
 529 be the same across different processes.
 530 In all other cases, the files are unique because it is possible to
 531 have two different dumps started at the same time, and separate
 532 operations shouldn't conflict with each other.
 533 .Pp
 534 To do a network restore, you have to run restore as root.  This is due
 535 to the previous security history of dump and restore.  (restore is
 536 written to be setuid root, but we are not certain all bugs are gone
 537 from the restore code - run setuid at your own risk.)
 538 .Sh AUTHOR
 539 The
 540 .Nm dump/restore
 541 backup suit was ported to Linux's Second Extended File System
 542 by Remy Card <card@Linux.EU.Org>. He maintained the initial versions
 543 of dump (up and including 0.4b4, released in january 1997).
 544 .Pp
 545 Starting with 0.4b5, the new maintainer is Stelian Pop
 546 .br
 547 <pop@cybercable.fr>.
 548 .Sh AVAILABILITY
 549 The
 550 .Nm dump/restore
 551 backup suit is available for anonymous ftp from tsx-11.mit.edu
 552 in /pub/linux/ALPHA/ext2fs (development versions) or
 553 /pub/linux/packages/ext2fs (stable versions).
 554 .Pp
 555 An alternate downloading location is http://perso.cybercable.fr/pop/dump.
 556 .Sh HISTORY
 557 The
 558 .Nm restore
 559 command appeared in
 560 .Bx 4.2 .