linux - restore (8)
NAME
restore - restore files or file systems from backups made with dump
SYNOPSIS
restore key [name ...]
DESCRIPTION
The restore command performs the inverse function of dump(8). A full
backup of a file system may be restored and subsequent incremental back-
ups layered on top of it. Single files and directory subtrees may be re-
stored from full or partial backups. Restore works across a network; to
do this see the -f flag described below. The actions of restore are con-
trolled by the given key, which 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. Unless the h key is specified (see be-
low), the appearance of a directory name refers to the files and (recur-
sively) subdirectories of that directory.
The function portion of the key is specified by one of the following let-
ters:
r Restore (rebuild a file system). The target file system should
be made pristine with newfs(8), mounted and the user cd'd into
the pristine file system before starting the restoration of the
initial level 0 backup. If the level 0 restores successfully, the
r key may be used to restore any necessary incremental backups on
top of the level 0. The r key precludes an interactive file ex-
traction and can be detrimental to one's health if not used care-
fully (not to mention the disk). An example:
newfs /dev/rrp0g eagle
mount /dev/rp0g /mnt
cd /mnt
restore rf /dev/rst8
Note that restore leaves a file restoresymtable in the root di-
rectory to pass information between incremental restore passes.
This file should be removed when the last incremental has been
restored.
Restore, in conjunction with newfs(8) and dump(8), may be used
to modify file system parameters such as size or block size.
C Restore reads the backup and compares its contents with files
present on the disk. It first changes its working directory to
the root of the filesystem that was dumped and compares the tape
with the files in its new current directory. This is useful to
check that the backup is correct.
R Restore requests a particular tape of a multi volume set on which
to restart a full restore (see the r key above). This is useful
if the restore has been interrupted.
i This mode allows interactive restoration of files from a dump.
After reading in the directory information from the dump, restore
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 re-
quire an argument, the default is the current directory.
add [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 h key is
specified on the command line). Files that are on
the extraction list are prepended with a ``*'' when
they are listed by ls.
cd arg Change the current working directory to the specified
argument.
delete [arg]
The current directory or specified argument is delet-
ed from the list of files to be extracted. If a di-
rectory is specified, then it and all its descendents
are deleted from the extraction list (unless the h
key is specified on the command line). The most ex-
pedient way to extract most of the files from a di-
rectory is to add the directory to the extraction
list and then delete those files that are not needed.
extract All the files that are on the extraction list are ex-
tracted from the dump. Restore 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.
help List a summary of the available commands.
ls [arg] List the current or specified directory. Entries
that are directories are appended with a ``/''. En-
tries 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.
pwd Print the full pathname of the current working direc-
tory.
quit Restore immediately exits, even if the extraction
list is not empty.
setmodes All the directories that have been added to the ex-
traction list have their owner, modes, and times set;
nothing is extracted from the dump. This is useful
tries to determine the media block size dynamically.
D The next argument to restore is used as the filesystem name used
by the -C option in its comparison.
f The next argument to restore is used as the name of the archive
instead of /dev/rmt?. If the name of the file is of the form
``host:file'', restore reads from the named file on the remote
host using rmt(8). If the name of the file is `-', restore reads
from standard input. Thus, dump(8) and restore can be used in a
pipeline to dump and restore a file system with the command
dump 0f - /usr | (cd /mnt; restore xf -)
h Restore extracts the actual directory, rather than the files that
it references. This prevents hierarchical restoration of com-
plete subtrees from the dump.
m Restore 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 to the file.
N Restore will not extract files. It will only print the file
names.
s The next argument to restore is a number which selects the file
on a multi-file dump tape. File numbering starts at 1.
T The next argument to restore is a directory to use for the stor-
age of temporary files. The default value is /tmp. This option
is most useful when restoring files after having booted from a
floppy. There might be little or no space on the floppy filesys-
tem, but another source of space might exist.
v Normally restore does its work silently. The v (verbose) key
causes it to type the name of each file it treats preceded by its
file type.
y Restore will not ask whether it should abort the restore if it
gets an error. It will always try to skip over the bad block(s)
and continue as best it can.
DIAGNOSTICS
Complaints about bad key characters.
Complaints if it gets a read error. If y has been specified, or the user
responds `y', restore will attempt to continue the restore.
If a backup was made using more than one tape volume, restore will notify
the user when it is time to mount the next volume. If the x or i key has
been specified, restore will also ask which volume the user wishes to
mount. The fastest way to extract a few files is to start with the last
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.
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.
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.
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.
Tape read error while restoring <filename>
Tape read error while skipping over inode <inumber>
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.
resync restore, skipped <num> blocks
After a dump read error, restore may have to resynchronize it-
self. This message lists the number of blocks that were skipped
over.
FILES
/dev/rmt? the default tape drive
/tmp/rstdir* file containing directories on the tape.
/tmp/rstmode* owner, mode, and time stamps for directories.
./restoresymtable information passed between incremental restores.
SEE ALSO
dump(8), newfs(8), mount(8), mkfs(8), rmt(8)
BUGS
Restore 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
dump must be done to get a new set of directories reflecting the new in-
ode numbering, even though the contents of the files is unchanged.
The Linux port of restore is not able yet to restore multi-volume back-
ups.