NAME
restore,
rrestore —
restore files or file systems from backups made with
dump
SYNOPSIS
restore |
-i
[-cdhmuvyN]
[-b bsize]
[-D
algorithm]
[-f file]
[-M mfile]
[-s
fileno] |
restore |
-R [-cduvyN]
[-b bsize]
[-D
algorithm]
[-f file]
[-M mfile]
[-s
fileno] |
restore |
-r [-cduvyN]
[-b bsize]
[-D
algorithm]
[-f file]
[-M mfile]
[-s
fileno] |
restore |
-t [-cdhuvy]
[-b bsize]
[-f file]
[-s
fileno]
[file ...] |
restore |
-x
[-cdhmuvyN]
[-b bsize]
[-D
algorithm]
[-f file]
[-M mfile]
[-s
fileno]
[file ...]
(The 4.3BSD option syntax is implemented for
backward compatibility, but is not documented here.) |
DESCRIPTION
The
restore command performs the inverse function of
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.
restore works across a network; to do this see the
-f flag described below. Other arguments to the command are
file or directory names specifying the files that are to be restored. Unless
the
-h flag is specified (see below), the appearance of a
directory name refers to the files and (recursively) subdirectories of that
directory.
If any file arguments are given with the
-x flag, or specified
in the command shell with the
-i flag, the permissions of
the root directory
will not be applied to the current
directory, unless one of those file arguments explicitly represents the root
inode (e.g.: a literal ‘.’). This is a change from the traditional
behaviour, which used to be to always prompt the user.
Exactly one of the following flags is required:
-
-
- -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 require 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 descendants are added to the extraction list (unless
the -h flag 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 deleted
from the list of files to be extracted. If a directory is specified,
then it and all its descendants are deleted from the extraction list
(unless the -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.
-
-
- extract
- All the files that are on the extraction list are
extracted 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 “/”. 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.
-
-
- pwd
- Print the full pathname of the current working
directory.
-
-
- quit,
xit
- Restore immediately exits, even if the extraction list
is not empty.
-
-
- 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.
-
-
- verbose
- The sense of the -v flag is toggled.
When set, the verbose flag causes the ls command to
list the inode numbers of all entries. It also causes
restore to print out information about each file as
it is extracted.
-
-
- what
- List dump header information.
-
-
- Debug
- Enable debugging.
-
-
- -R
- restore requests a particular tape of a
multi volume set on which to restart a full restore (see the
-r flag below). This is useful if the restore has been
interrupted.
-
-
- -r
- Restore (rebuild a file system). The target file system
should be made pristine with
newfs(8), mounted and the
user cd(1)'d into the pristine
file system before starting the restoration of the initial level 0 backup.
If the level 0 restores successfully, the -r flag may be
used to restore any necessary incremental backups on top of the level 0.
The -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:
newfs /dev/rsd0g
mount /dev/sd0g /mnt
cd /mnt
restore rf /dev/rst0
Note that restore leaves a file
restoresymtable in the root directory 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.
-
-
- -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 -h flag has been specified. Note that the
-t flag replaces the function of the old
dumpdir program.
-
-
- -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
-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 -h flag has been specified.
The following additional options may be specified:
-
-
- -b
bsize
- The number of kilobytes per dump record. If the
-b option is not specified, restore
tries to determine the block size dynamically.
-
-
- -c
- Normally, restore will try to determine
dynamically whether the dump was made from an old (pre-4.4) or new format
file system. The -c flag disables this check, and only
allows reading a dump in the old format.
-
-
- -D
algorithm
- Computes the digest of each regular files using the
algorithm and output to standard output. The
algorithm is one of md5,
rmd160, or sha1. This option
doesn't imply -N.
-
-
- -d
- Enable debugging.
-
-
- -f
file
- Read the backup from file;
file may be a special device file like
/dev/rst0 (a tape drive), /dev/rsd1c
(a disk drive), an ordinary file, or
‘
-
’ (the standard
input). If the name of the file is of the form “host:file”, or
“user@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
- Extract the actual directory, rather than the files that it
references. This prevents hierarchical restoration of complete subtrees
from the dump.
-
-
- -M
mfile
- Do not set the file flags on restore. Instead, append an
mtree(8) specification to
mfile, which can be used to restore file flags with
a command such as
sort mfile | mtree -e -i -u
-
-
- -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.
-
-
- -N
- Do not perform actual writing to disk.
-
-
- -s
fileno
- Read from the specified fileno on a
multi-file tape. File numbering starts at 1.
-
-
- -u
- The -u (unlink) flag removes files before
extracting them. This is useful when an executable file is in use. Ignored
if -t or -N flag is given.
-
-
- -v
- Normally restore does its work silently.
The -v (verbose) flag causes it to type the name of each
file it treats preceded by its file type.
-
-
- -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.
ENVIRONMENT
If the following environment variable exists it will be used by
restore:
- TMPDIR
- The directory given in TMPDIR will be used instead of
/tmp to store temporary files. Refer to
environ(7) for more
information.
FILES
- /dev/nrst0
- default tape unit to use. Taken from
_PATH_DEFTAPE
in
/usr/include/paths.h.
- /dev/rst*
- raw SCSI tape interface
- /tmp/rstdir*
- file containing directories on the tape.
- /tmp/rstmode*
- owner, mode, and time stamps for directories.
- ./restoresymtable
- information passed between incremental restores.
DIAGNOSTICS
Complains 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 flag 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 volume, and
work towards the first volume.
There are numerous consistency checks that can be listed by
restore. Most checks are self-explanatory or can
“never happen”. Common errors are given below.
- 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.
- <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.
- 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 itself. This message lists the number of blocks that were
skipped over.
SEE ALSO
rcmd(1),
rcmd(3),
environ(7),
dump(8),
mount(8),
newfs(8),
rmt(8)
HISTORY
The
restore command appeared in
4.2BSD.
BUGS
restore can get confused when doing incremental restores from
dumps that were made on active file systems.
A level zero dump must be done after a full restore. Because
restore runs in user mode, 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 content of the files is
unchanged.
The temporary files
/tmp/rstdir* and
/tmp/rstmode* are generated with a unique name based on the
date of the dump and the process ID (see
mktemp(3)), except for when
-r or
-R is used. Because
-R allows you to restart a
-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 shouldn't conflict with each other.