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.\" @(#)restore.8 6.10 (Berkeley) 7/23/91
.Nd "restore files or file systems from backups made with dump"
command performs the inverse function of
A full backup of a file system may be restored and
subsequent incremental backups layered on top of it.
directory subtrees may be restored from full or partial
cannot work across a network, to do this, see the companion
are controlled by the given
is a string of characters containing
at most one function letter and possibly
one or more function modifiers.
Other arguments to the command are file or directory
names specifying the files that are to be restored.
key is specified (see below),
the appearance of a directory name refers to
the files and (recursively) subdirectories of that directory.
the key is specified by one of the following letters:
Restore (rebuild a file system).
The target file system should be made pristine with
into the pristine file system
before starting the restoration of the initial level 0 backup. If the
level 0 restores successfully, the
key may be used to restore
any necessary incremental backups on top of the level 0.
key precludes an interactive file extraction and can be
detrimental to ones health if not used carefully (not to mention
.Bd -literal -offset indent
in the root directory to pass information between incremental
This file should be removed when the last incremental has been
may be used to modify file system parameters
such as size or block size.
requests a particular tape of a multi volume set on which to restart
This is useful if the restore has been interrupted.
The named files are read from the given media.
If a named file matches a directory whose contents
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
The names of the specified files are listed if they occur
If no file argument is given,
then the root directory is listed,
which results in the entire content of the
key replaces the function of the old
This mode allows interactive restoration of files from a dump.
After reading in the directory information from the dump,
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.
The current directory or specified argument is added to the list of
If a directory is specified, then it and all its descendents are
added to the extraction list
key is specified on the command line).
Files that are on the extraction list are prepended with a ``*''
Change the current working directory to the specified argument.
The current directory or specified argument is deleted from the list of
If a directory is specified, then it and all its descendents are
deleted from the extraction list
key 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.
All the files that are on the extraction list are extracted
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.
List a summary of the available commands.
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 key is set the inode number of each entry is also listed.
Print the full pathname of the current working directory.
Restore immediately exits,
even if the extraction list is not empty.
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.
When set, the verbose key causes the
command to list the inode numbers of all entries.
to print out information about each file as it is extracted.
The following characters may be used in addition to the letter
that selects the function desired.
is used as the block size of the media (in kilobytes).
tries to determine the media block size dynamically.
is used as the name of the archive instead
If the name of the file is
reads from standard input.
can be used in a pipeline to dump and restore a file system
.Bd -literal -offset indent
dump 0f - /usr | (cd /mnt; restore xf -)
extracts the actual directory,
rather than the files that it references.
This prevents hierarchical restoration of complete subtrees
will 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
selects the file on a multi-file dump tape. File numbering
key causes it to type the name of each file it treats
preceded by its file type.
will not ask whether it should abort the restore if gets an error.
It will always try to skip over the bad block(s) and continue as
Complaints about bad key characters.
Complaints if it gets a read error.
has been specified, or the user responds
will attempt to continue the restore.
If a backup was made using more than one tape volume,
will notify the user when it is time to mount the next volume.
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.
There are numerous consistency checks that can be listed by
Most checks are self-explanatory or can ``never happen''.
Common errors are given below.
.Bl -tag -width Ds -compact
.It Converting to new file system format.
A dump tape created from the old file system has been loaded.
It is automatically converted to the new file system format.
.It <filename>: 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.
.It expected next file <inumber>, got <inumber>
A file that was not listed in the directory showed up.
This can occur when using a dump created on an active file system.
.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.
.It Incremental dump too high
When doing incremental restore,
a dump that does not begin its coverage where the previous incremental
or that has too high an incremental level has been loaded.
.It Tape read error while restoring <filename>
.It Tape read error while skipping over inode <inumber>
.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.
.It resync restore, skipped <num> blocks
may have to resynchronize itself.
This message lists the number of blocks that were skipped over.
.Bl -tag -width "./restoresymtable" -compact
file containing directories on the tape.
owner, mode, and time stamps for directories.
.It Pa \&./restoresymtable
information passed between incremental restores.
can get confused when doing incremental restores from
dump that were made on active file systems.
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 restore must be done to get a new set of directories
reflecting the new inode numbering,
even though the contents of the files is unchanged.