Index: head/sbin/dump/dump.8 =================================================================== --- head/sbin/dump/dump.8 (revision 235836) +++ head/sbin/dump/dump.8 (revision 235837) @@ -1,570 +1,568 @@ .\" Copyright (c) 1980, 1991, 1993 .\" Regents of the University of California. .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)dump.8 8.3 (Berkeley) 5/1/95 .\" $FreeBSD$ .\" .Dd February 24, 2006 .Dt DUMP 8 .Os .Sh NAME .Nm dump , .Nm rdump .Nd file system backup .Sh SYNOPSIS .Nm .Op Fl 0123456789acLnrRSu .Op Fl B Ar records .Op Fl b Ar blocksize .Op Fl C Ar cachesize .Op Fl D Ar dumpdates .Op Fl d Ar density .Op Fl f Ar file | Fl P Ar pipecommand .Op Fl h Ar level .Op Fl s Ar feet .Op Fl T Ar date .Ar filesystem .Nm .Fl W | Fl w -.Pp -.Nm rdump -is an alternate name for -.Nm . -.Pp -.in \" XXX -(The -.Bx 4.3 -option syntax is implemented for backward compatibility, but -is not documented here.) .Sh DESCRIPTION The .Nm utility examines files on a file system and determines which files need to be backed up. These files are copied to the given disk, tape or other storage medium for safe keeping (see the .Fl f option below for doing remote backups). A dump that is larger than the output medium is broken into multiple volumes. On most media the size is determined by writing until an end-of-media indication is returned. This can be enforced by using the .Fl a option. .Pp On media that cannot reliably return an end-of-media indication (such as some cartridge tape drives) each volume is of a fixed size; the actual size is determined by the tape size and density and/or .Fl B options. By default, the same output file name is used for each volume after prompting the operator to change media. .Pp The file system to be dumped is specified by the argument .Ar filesystem as either its device-special file or its mount point (if that is in a standard entry in .Pa /etc/fstab ) . +.Pp +.Nm +may also be invoked as +.Nm rdump . +The +.Bx 4.3 +option syntax is implemented for backward compatibility, but +is not documented here. .Pp The following options are supported by .Nm : .Bl -tag -width Ds .It Fl 0-9 Dump levels. A level 0, full backup, guarantees the entire file system is copied (but see also the .Fl h option below). A level number above 0, incremental backup, tells dump to copy all files new or modified since the last dump of any lower level. The default level is 0. .It Fl a .Dq auto-size . Bypass all tape length considerations, and enforce writing until an end-of-media indication is returned. This fits best for most modern tape drives. Use of this option is particularly recommended when appending to an existing tape, or using a tape drive with hardware compression (where you can never be sure about the compression ratio). .It Fl B Ar records The number of kilobytes per output volume, except that if it is not an integer multiple of the output block size, the command uses the next smaller such multiple. This option overrides the calculation of tape size based on length and density. .It Fl b Ar blocksize The number of kilobytes per output block. The default block size is 10. .It Fl C Ar cachesize Specify the cache size in megabytes. This will greatly improve performance at the cost of .Nm possibly not noticing changes in the file system between passes. It is recommended that you always use this option when dumping a snapshot. Beware that .Nm forks, and the actual memory use may be larger than the specified cache size. The recommended cache size is between 8 and 32 (megabytes). .It Fl c Change the defaults for use with a cartridge tape drive, with a density of 8000 bpi, and a length of 1700 feet. .It Fl D Ar dumpdates Specify an alternate path to the .Pa dumpdates file. The default is .Pa /etc/dumpdates . .It Fl d Ar density Set tape density to .Ar density . The default is 1600BPI. .It Fl f Ar file Write the backup to .Ar file ; .Ar file may be a special device file like .Pa /dev/sa0 (a tape drive), .Pa /dev/fd1 (a floppy disk drive), an ordinary file, or .Sq Fl (the standard output). Multiple file names may be given as a single argument separated by commas. Each file will be used for one dump volume in the order listed; if the dump requires more volumes than the number of names given, the last file name will used for all remaining volumes after prompting for media changes. If the name of the file is of the form .Dq host:file , or .Dq user@host:file , .Nm writes to the named file on the remote host using .Xr rmt 8 . The default path name of the remote .Xr rmt 8 program is .\" rmt path, is the path on the remote host .Pa /etc/rmt ; this can be overridden by the environment variable .Ev RMT . .It Fl P Ar pipecommand Use .Xr popen 3 to execute the .Xr sh 1 script string defined by .Ar pipecommand for the output device of each volume. This child pipeline's .Dv stdin .Pq Pa /dev/fd/0 is redirected from the .Nm output stream, and the environment variable .Ev DUMP_VOLUME is set to the current volume number being written. After every volume, the writer side of the pipe is closed and .Ar pipecommand is executed again. Subject to the media size specified by .Fl B , each volume is written in this manner as if the output were a tape drive. .It Fl h Ar level Honor the user .Dq nodump flag .Pq Dv UF_NODUMP only for dumps at or above the given .Ar level . The default honor level is 1, so that incremental backups omit such files but full backups retain them. .It Fl L This option is to notify .Nm that it is dumping a live file system. To obtain a consistent dump image, .Nm takes a snapshot of the file system in the .Pa .snap directory in the root of the file system being dumped and then does a dump of the snapshot. The snapshot is unlinked as soon as the dump starts, and is thus removed when the dump is complete. This option is ignored for unmounted or read-only file systems. If the .Pa .snap directory does not exist in the root of the file system being dumped, a warning will be issued and the .Nm will revert to the standard behavior. This problem can be corrected by creating a .Pa .snap directory in the root of the file system to be dumped; its owner should be .Dq Li root , its group should be .Dq Li operator , and its mode should be .Dq Li 0770 . .It Fl n Whenever .Nm requires operator attention, notify all operators in the group .Dq operator by means similar to a .Xr wall 1 . .It Fl r Be rsync-friendly. Normally dump stores the date of the current and prior dump in numerous places throughout the dump. These scattered changes significantly slow down rsync or another incremental file transfer program when they are used to update a remote copy of a level 0 dump, since the date changes for each dump. This option sets both dates to the epoch, permitting rsync to be much more efficient when transferring a dump file. .It Fl R Be even more rsync-friendly. This option disables the storage of the actual inode access time (storing it instead as the inode's modified time). This option permits rsync to be even more efficient when transferring dumps generated from filesystems with numerous files which are not changing other than their access times. The .Fl R option also sets .Fl r . .It Fl S Display an estimate of the backup size and the number of tapes required, and exit without actually performing the dump. .It Fl s Ar feet Attempt to calculate the amount of tape needed at a particular density. If this amount is exceeded, .Nm prompts for a new tape. It is recommended to be a bit conservative on this option. The default tape length is 2300 feet. .It Fl T Ar date Use the specified date as the starting time for the dump instead of the time determined from looking in the .Pa dumpdates file. The format of date is the same as that of .Xr ctime 3 . This option is useful for automated dump scripts that wish to dump over a specific period of time. The .Fl T option is mutually exclusive from the .Fl u option. .It Fl u Update the .Pa dumpdates file after a successful dump. The format of the .Pa dumpdates file is readable by people, consisting of one free format record per line: file system name, increment level and .Xr ctime 3 format dump date. There may be only one entry per file system at each level. The .Pa dumpdates file may be edited to change any of the fields, if necessary. The default path for the .Pa dumpdates file is .Pa /etc/dumpdates , but the .Fl D option may be used to change it. .It Fl W Tell the operator what file systems need to be dumped. This information is gleaned from the files .Pa dumpdates and .Pa /etc/fstab . The .Fl W option causes .Nm to print out, for each file system in the .Pa dumpdates file the most recent dump date and level, and highlights those file systems that should be dumped. If the .Fl W option is set, all other options are ignored, and .Nm exits immediately. .It Fl w Is like .Fl W , but prints only those file systems which need to be dumped. .El .Pp Directories and regular files which have their .Dq nodump flag .Pq Dv UF_NODUMP set will be omitted along with everything under such directories, subject to the .Fl h option. .Pp The .Nm utility requires operator intervention on these conditions: end of tape, end of dump, tape write error, tape open error or disk read error (if there are more than a threshold of 32). In addition to alerting all operators implied by the .Fl n key, .Nm interacts with the operator on .Em dump's control terminal at times when .Nm can no longer proceed, or if something is grossly wrong. All questions .Nm poses .Em must be answered by typing .Dq yes or .Dq no , appropriately. .Pp Since making a dump involves a lot of time and effort for full dumps, .Nm checkpoints itself at the start of each tape volume. If writing that volume fails for some reason, .Nm will, with operator permission, restart itself from the checkpoint after the old tape has been rewound and removed, and a new tape has been mounted. .Pp The .Nm utility tells the operator what is going on at periodic intervals (every 5 minutes, or promptly after receiving .Dv SIGINFO ) , including usually low estimates of the number of blocks to write, the number of tapes it will take, the time to completion, and the time to the tape change. The output is verbose, so that others know that the terminal controlling .Nm is busy, and will be for some time. .Pp In the event of a catastrophic disk event, the time required to restore all the necessary backup tapes or files to disk can be kept to a minimum by staggering the incremental dumps. An efficient method of staggering incremental dumps to minimize the number of tapes follows: .Bl -bullet -offset indent .It Always start with a level 0 backup, for example: .Bd -literal -offset indent /sbin/dump -0u -f /dev/nsa0 /usr/src .Ed .Pp This should be done at set intervals, say once a month or once every two months, and on a set of fresh tapes that is saved forever. .It After a level 0, dumps of active file systems (file systems with files that change, depending on your partition layout some file systems may contain only data that does not change) are taken on a daily basis, using a modified Tower of Hanoi algorithm, with this sequence of dump levels: .Bd -literal -offset indent 3 2 5 4 7 6 9 8 9 9 ... .Ed .Pp For the daily dumps, it should be possible to use a fixed number of tapes for each day, used on a weekly basis. Each week, a level 1 dump is taken, and the daily Hanoi sequence repeats beginning with 3. For weekly dumps, another fixed set of tapes per dumped file system is used, also on a cyclical basis. .El .Pp After several months or so, the daily and weekly tapes should get rotated out of the dump cycle and fresh tapes brought in. .Sh ENVIRONMENT .Bl -tag -width ".Ev TAPE" .It Ev TAPE The .Ar file or device to dump to if the .Fl f option is not used. .It Ev RMT Pathname of the remote .Xr rmt 8 program. .It Ev RSH Pathname of a remote shell program, if not .Xr rsh 1 . .El .Sh FILES .Bl -tag -width /etc/dumpdates -compact .It Pa /dev/sa0 default tape unit to dump to .It Pa /etc/dumpdates dump date records (this can be changed; see the .Fl D option) .It Pa /etc/fstab dump table: file systems and frequency .It Pa /etc/group to find group .Em operator .El .Sh EXIT STATUS Dump exits with zero status on success. Startup errors are indicated with an exit code of 1; abnormal termination is indicated with an exit code of 3. .Sh EXAMPLES Dumps the .Pa /u file system to DVDs using .Nm growisofs . Uses a 16MB cache, creates a snapshot of the dump, and records the .Pa dumpdates file. .Bd -literal /sbin/dump -0u -L -C16 -B4589840 -P 'growisofs -Z /dev/cd0=/dev/fd/0' /u .Ed .Sh DIAGNOSTICS Many, and verbose. .Sh SEE ALSO .Xr chflags 1 , .Xr fstab 5 , .Xr restore 8 , .Xr rmt 8 .Sh HISTORY A .Nm utility appeared in .At v6 . .Sh BUGS Fewer than 32 read errors on the file system are ignored, though all errors will generate a warning message. This is a bit of a compromise. In practice, it is possible to generate read errors when doing dumps on mounted partitions if the file system is being modified while the .Nm is running. Since dumps are often done in an unattended fashion using .Xr cron 8 jobs asking for Operator intervention would result in the .Nm dying. However, there is nothing wrong with a dump tape written when this sort of read error occurs, and there is no reason to terminate the .Nm . .Pp Each reel requires a new process, so parent processes for reels already written just hang around until the entire tape is written. .Pp The .Nm utility with the .Fl W or .Fl w options does not report file systems that have never been recorded in the .Pa dumpdates file, even if listed in .Pa /etc/fstab . .Pp It would be nice if .Nm knew about the dump sequence, kept track of the tapes scribbled on, told the operator which tape to mount when, and provided more assistance for the operator running .Xr restore 8 . .Pp The .Nm utility cannot do remote backups without being run as root, due to its security history. This will be fixed in a later version of .Fx . Presently, it works if you set it setuid (like it used to be), but this might constitute a security risk. Index: head/sbin/restore/restore.8 =================================================================== --- head/sbin/restore/restore.8 (revision 235836) +++ head/sbin/restore/restore.8 (revision 235837) @@ -1,505 +1,503 @@ .\" Copyright (c) 1985, 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)restore.8 8.4 (Berkeley) 5/1/95 .\" $FreeBSD$ .\" .Dd October 12, 2006 .Dt RESTORE 8 .Os .Sh NAME .Nm restore , .Nm rrestore .Nd "restore files or file systems from backups made with dump" .Sh SYNOPSIS .Nm .Fl i .Op Fl dDhmNuvy .Op Fl b Ar blocksize .Op Fl f Ar file | Fl P Ar pipecommand .Op Fl s Ar fileno .Nm .Fl R .Op Fl dDNuvy .Op Fl b Ar blocksize .Op Fl f Ar file | Fl P Ar pipecommand .Op Fl s Ar fileno .Nm .Fl r .Op Fl dDNuvy .Op Fl b Ar blocksize .Op Fl f Ar file | Fl P Ar pipecommand .Op Fl s Ar fileno .Nm .Fl t .Op Fl dDhNuvy .Op Fl b Ar blocksize .Op Fl f Ar file | Fl P Ar pipecommand .Op Fl s Ar fileno .Op Ar .Nm .Fl x .Op Fl dDhmNuvy .Op Fl b Ar blocksize .Op Fl f Ar file | Fl P Ar pipecommand .Op Fl s Ar fileno .Op Ar -.Pp -.Nm rrestore -is an alternate name for -.Nm . -.Pp -.in \" XXX -(The -.Bx 4.3 -option syntax is implemented for backward compatibility, but -is not documented here.) .Sh DESCRIPTION The .Nm utility performs the inverse function of .Xr dump 8 . A full backup of a file system may be restored and subsequent incremental backups layered on top of it. Single files and directory subtrees may be restored from full or partial backups. The .Nm utility works across a network; to do this see the .Fl f and .Fl P flags described below. Other arguments to the command are file or directory names specifying the files that are to be restored. Unless the .Fl h flag is specified (see below), the appearance of a directory name refers to the files and (recursively) subdirectories of that directory. +.Pp +.Nm +may also be invoked as +.Nm rrestore . +The +.Bx 4.3 +option syntax is implemented for backward compatibility, but +is not documented here. .Pp Exactly one of the following flags is required: .Bl -tag -width Ds .It Fl i This mode allows interactive restoration of files from a dump. After reading in the directory information from the dump, .Nm provides a shell like interface that allows the user to move around the directory tree selecting files to be extracted. The available commands are given below; for those commands that require an argument, the default is the current directory. .Bl -tag -width Fl .It Ic add Op Ar arg The current directory or specified argument is added to the list of files to be extracted. If a directory is specified, then it and all its descendents are added to the extraction list (unless the .Fl h flag is specified on the command line). Files that are on the extraction list are prepended with a ``*'' when they are listed by .Ic ls . .It Ic \&cd Ar arg Change the current working directory to the specified argument. .It Ic delete Op Ar arg The current directory or specified argument is deleted from the list of files to be extracted. If a directory is specified, then it and all its descendents are deleted from the extraction list (unless the .Fl h flag is specified on the command line). The most expedient way to extract most of the files from a directory is to add the directory to the extraction list and then delete those files that are not needed. .It Ic extract All the files that are on the extraction list are extracted from the dump. The .Nm utility will ask which volume the user wishes to mount. The fastest way to extract a few files is to start with the last volume, and work towards the first volume. .It Ic help List a summary of the available commands. .It Ic \&ls Op Ar arg List the current or specified directory. Entries that are directories are appended with a ``/''. Entries that have been marked for extraction are prepended with a ``*''. If the verbose flag is set the inode number of each entry is also listed. .It Ic pwd Print the full pathname of the current working directory. .It Ic quit Exit immediately, even if the extraction list is not empty. .It Ic setmodes All the directories that have been added to the extraction list have their owner, modes, and times set; nothing is extracted from the dump. This is useful for cleaning up after a restore has been prematurely aborted. .It Ic verbose The sense of the .Fl v flag is toggled. When set, the verbose flag causes the .Ic ls command to list the inode numbers of all entries. It also causes .Nm to print out information about each file as it is extracted. .It Ic what Display dump header information, which includes: date, level, label, and the file system and host dump was made from. .El .It Fl R Request a particular tape of a multi volume set on which to restart a full restore (see the .Fl r flag below). This is useful if the restore has been interrupted. .It Fl r Restore (rebuild a file system). The target file system should be made pristine with .Xr newfs 8 , mounted and the user .Xr cd 1 Ns 'd into the pristine file system before starting the restoration of the initial level 0 backup. If the level 0 restores successfully, the .Fl r flag may be used to restore any necessary incremental backups on top of the level 0. The .Fl r flag precludes an interactive file extraction and can be detrimental to one's health if not used carefully (not to mention the disk). An example: .Bd -literal -offset indent newfs /dev/da0s1a mount /dev/da0s1a /mnt cd /mnt restore rf /dev/sa0 .Ed .Pp Note that .Nm leaves a file .Pa restoresymtable in the root directory to pass information between incremental restore passes. This file should be removed when the last incremental has been restored. .Pp The .Nm utility , in conjunction with .Xr newfs 8 and .Xr dump 8 , may be used to modify file system parameters such as size or block size. .It Fl t The names of the specified files are listed if they occur on the backup. If no file argument is given, then the root directory is listed, which results in the entire content of the backup being listed, unless the .Fl h flag has been specified. Note that the .Fl t flag replaces the function of the old .Xr dumpdir 8 program. .It Fl x The named files are read from the given media. If a named file matches a directory whose contents are on the backup and the .Fl h flag is not specified, the directory is recursively extracted. The owner, modification time, and mode are restored (if possible). If no file argument is given, then the root directory is extracted, which results in the entire content of the backup being extracted, unless the .Fl h flag has been specified. .El .Pp The following additional options may be specified: .Bl -tag -width Ds .It Fl b Ar blocksize The number of kilobytes per dump record. If the .Fl b option is not specified, .Nm tries to determine the media block size dynamically. .It Fl d Sends verbose debugging output to the standard error. .It Fl D This puts .Nm into degraded mode, causing restore to operate less efficiently but to try harder to read corrupted backups. .It Fl f Ar file Read the backup from .Ar file ; .Ar file may be a special device file like .Pa /dev/sa0 (a tape drive), .Pa /dev/da1c (a disk drive), an ordinary file, or .Sq Fl (the standard input). If the name of the file is of the form .Dq host:file , or .Dq user@host:file , .Nm reads from the named file on the remote host using .Xr rmt 8 . .It Fl P Ar pipecommand Use .Xr popen 3 to execute the .Xr sh 1 script string defined by .Ar pipecommand as the input for every volume in the backup. This child pipeline's .Dv stdout .Pq Pa /dev/fd/1 is redirected to the .Nm input stream, and the environment variable .Ev RESTORE_VOLUME is set to the current volume number being read. The .Ar pipecommand script is started each time a volume is loaded, as if it were a tape drive. .It Fl h Extract the actual directory, rather than the files that it references. This prevents hierarchical restoration of complete subtrees from the dump. .It Fl m Extract by inode numbers rather than by file name. This is useful if only a few files are being extracted, and one wants to avoid regenerating the complete pathname to the file. .It Fl N Do the extraction normally, but do not actually write any changes to disk. This can be used to check the integrity of dump media or other test purposes. .It Fl s Ar fileno Read from the specified .Ar fileno on a multi-file tape. File numbering starts at 1. .It Fl u When creating certain types of files, restore may generate a warning diagnostic if they already exist in the target directory. To prevent this, the .Fl u (unlink) flag causes restore to remove old entries before attempting to create new ones. .It Fl v Normally .Nm does its work silently. The .Fl v (verbose) flag causes it to type the name of each file it treats preceded by its file type. .It Fl y Do not ask the user whether to abort the restore in the event of an error. Always try to skip over the bad block(s) and continue. .El .Sh ENVIRONMENT .Bl -tag -width ".Ev TMPDIR" .It Ev TAPE Device from which to read backup. .It Ev TMPDIR Name of directory where temporary files are to be created. .El .Sh FILES .Bl -tag -width "./restoresymtable" -compact .It Pa /dev/sa0 the default tape drive .It Pa /tmp/rstdir* file containing directories on the tape. .It Pa /tmp/rstmode* owner, mode, and time stamps for directories. .It Pa \&./restoresymtable information passed between incremental restores. .El .Sh DIAGNOSTICS The .Nm utility complains if it gets a read error. If .Fl y has been specified, or the user responds .Ql y , .Nm will attempt to continue the restore. .Pp If a backup was made using more than one tape volume, .Nm will notify the user when it is time to mount the next volume. If the .Fl x or .Fl i flag has been specified, .Nm will also ask which volume the user wishes to mount. The fastest way to extract a few files is to start with the last volume, and work towards the first volume. .Pp There are numerous consistency checks that can be listed by .Nm . Most checks are self-explanatory or can ``never happen''. Common errors are given below. .Pp .Bl -tag -width Ds -compact .It : not found on tape The specified file name was listed in the tape directory, but was not found on the tape. This is caused by tape read errors while looking for the file, and from using a dump tape created on an active file system. .Pp .It expected next file , got A file that was not listed in the directory showed up. This can occur when using a dump created on an active file system. .Pp .It Incremental dump too low When doing incremental restore, a dump that was written before the previous incremental dump, or that has too low an incremental level has been loaded. .Pp .It Incremental dump too high When doing incremental restore, a dump that does not begin its coverage where the previous incremental dump left off, or that has too high an incremental level has been loaded. .Pp .It Tape read error while restoring .It Tape read error while skipping over inode .It Tape read error while trying to resynchronize A tape (or other media) read error has occurred. If a file name is specified, then its contents are probably partially wrong. If an inode is being skipped or the tape is trying to resynchronize, then no extracted files have been corrupted, though files may not be found on the tape. .Pp .It resync restore, skipped blocks After a dump read error, .Nm may have to resynchronize itself. This message lists the number of blocks that were skipped over. .El .Sh SEE ALSO .Xr dump 8 , .Xr mount 8 , .Xr newfs 8 , .Xr rmt 8 .Sh HISTORY The .Nm utility appeared in .Bx 4.2 . .Sh BUGS The .Nm utility can get confused when doing incremental restores from dumps that were made on active file systems without the .Fl L option (see .Xr dump 8 ) . .Pp A level zero dump must be done after a full restore. Because restore runs in user code, it has no control over inode allocation; thus a full dump must be done to get a new set of directories reflecting the new inode numbering, even though the contents of the files is unchanged. .Pp To do a network restore, you have to run restore as root. This is due to the previous security history of dump and restore. (restore is written to be setuid root, but we are not certain all bugs are gone from the restore code - run setuid at your own risk.) .Pp The temporary files .Pa /tmp/rstdir* and .Pa /tmp/rstmode* are generated with a unique name based on the date of the dump and the process ID (see .Xr mktemp 3 ) , except for when .Fl r or .Fl R is used. Because .Fl R allows you to restart a .Fl r operation that may have been interrupted, the temporary files should be the same across different processes. In all other cases, the files are unique because it is possible to have two different dumps started at the same time, and separate operations should not conflict with each other.