Learn the UNIX/Linux command line
Home Man Pages
RESTORE(8) System management commands RESTORE(8)
NAME
restore - restore files or file systems from backups made with dump
SYNOPSIS
restore -C [-cdklMvVy] [-b blocksize] [-D filesystem] [-f file] [-F
script] [-L limit] [-s fileno] [-T directory]
restore -i [-acdhklmMNouvVy] [-A file] [-b blocksize] [-f file] [-F
script] [-Q file] [-s fileno] [-T directory]
restore -P file [-acdhklmMNuvVy] [-A file] [-b blocksize] [-f file]
[-F script] [-s fileno] [-T directory] [-X filelist] [ file ... ]
restore -R [-cdklMNuvVy] [-b blocksize] [-f file] [-F script] [-s
fileno] [-T directory]
restore -r [-cdklMNuvVy] [-b blocksize] [-f file] [-F script] [-s
fileno] [-T directory]
restore -t [-cdhklMNuvVy] [-A file] [-b blocksize] [-f file] [-F
script] [-Q file] [-s fileno] [-T directory] [-X filelist] [ file ...
]
restore -x [-adchklmMNouvVy] [-A file] [-b blocksize] [-f file] [-F
script] [-Q file] [-s fileno] [-T directory] [-X filelist] [ file ...
]
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 net-
work; 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.
Exactly one of the following flags is required:
-C This mode allows comparison of files from a dump. 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. See also the -L flag
described below.
-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 descendents 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 descendents 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 files 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 f ew 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 direc-
tory.
quit Restore immediately exits, even if the extraction list
is not empty.
setmodes
All 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 ver-
bose flag causes the ls command to list the inode num-
bers of all entries. It also causes restore to print out
information about each file as it is extracted.
-P file
Restore creates a new Quick File Access file file from an
existing dump file without restoring its contents.
-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 mke2fs(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 success-
fully, the -r flag may be used to restore any necessary incre-
mental backups on top of the level 0. The -r flag precludes an
interactive file extraction and can be detrimental to one's
health (not to mention the disk) if not used carefully. An
example:
mke2fs /dev/sda1
mount /dev/sda1 /mnt
cd /mnt
restore rf /dev/st0
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 mke2fs(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, 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(8) program.
See also the -X option below.
-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 possi-
ble). If no file argument is given, the root directory is
extracted, which results in the entire content of the backup
being extracted, unless the -h flag has been specified. See
also the -X option below.
OPTIONS
The following additional options may be specified:
-a In -i or -x mode, restore does ask the user for the volume num-
ber on which the files to be extracted are supposed to be (in
order to minimise the time by reading only the interesting vol-
umes). The -a option disables this behaviour and reads all the
volumes starting with 1. This option is useful when the opera-
tor does not know on which volume the files to be extracted are
and/or when he prefers the longer unattended mode rather than
the shorter interactive mode.
-A archive_file
Read the table of contents from archive_file instead of the
media. This option can be used in combination with the -t, -i,
or -x options, making it possible to check whether files are on
the media without having to mount the media.
-b blocksize
The number of kilobytes per dump record. If the -b option is
not specified, restore tries to determine the media 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 The -d (debug) flag causes restore to print debug information.
-D filesystem
The -D flag allows the user to specify the filesystem name when
using restore with the -C option to check the backup.
-f file
Read the backup from file; file may be a special device file
like /dev/st0 (a tape drive), /dev/sda1 (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).
-F script
Run script at the beginning of each tape. The device name and
the current volume number are passed on the command line. The
script must return 0 if restore should continue without asking
the user to change the tape, 1 if restore should continue but
ask the user to change the tape. Any other exit code will cause
restore to abort. For security reasons, restore reverts back to
the real user ID and the real group ID before running the
script.
-h Extract the actual directory, rather than the files that it
references. This prevents hierarchical restoration of complete
subtrees from the dump.
-k Use Kerberos authentication when contacting the remote tape
server. (Only available if this options was enabled when
restore was compiled.)
-l When doing remote restores, assume the remote file is a regular
file (instead of a tape device). If you're restoring a remote
compressed file, you will need to specify this option or
restore will fail to access it correctly.
-L limit
The -L flag allows the user to specify a maximal number of mis-
compares when using restore with the -C option to check the
backup. If this limit is reached, restore will abort with an
error message. A value of 0 (the default value) disables the
check.
-m Extract by inode numbers rather than by file name. This is use-
ful if only a few files are being extracted, and one wants to
avoid regenerating the complete pathname to the file.
-M Enables the multi-volume feature (for reading dumps made using
the -M option of dump). The name specified with -f is treated
as a prefix and restore tries to read in sequence from 001, 002 etc.
-N The -N flag causes restore to perform a full execution as
requested by one of -i, -R, -r, t or x command without actually
writing any file on disk.
-o The -o flag causes restore to automatically restore the current
directory permissions without asking the operator whether to do
so in one of -i or -x modes.
-Q file
Use the file file in order to read tape position as stored
using the dump Quick File Access mode, in one of -i, -x or -t
mode.
It is recommended to set up the st driver to return logical
tape positions rather than physical before calling dump/restore
with parameter -Q. Since not all tape devices support physical
tape positions those tape devices return an error during
dump/restore when the st driver is set to the default physical
setting. Please see the st(4) man page, option MTSETDRVBUFFER ,
or the mt(1) man page, on how to set the driver to return logi-
cal tape positions.
Before calling restore with parameter -Q, always make sure the
st driver is set to return the same type of tape position used
during the call to dump. Otherwise restore may be confused.
This option can be used when restoring from local or remote
tapes (see above) or from local or remote files.
-s fileno
Read from the specified fileno on a multi-file tape. File num-
bering starts at 1.
-T directory
The -T flag allows the user to specify a directory to use for
the storage of temporary files. The default value is /tmp.
This flag is most useful when restoring files after having
booted from a floppy. There might be little or no space on the
floppy filesystem, but another source of space might exist.
-u When creating certain types of files, restore may generate a
warning diagnostic if they already exist in the target direc-
tory. To prevent this, the -u (unlink) flag causes restore to
remove old entries before attempting to create new ones.
-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.
-V Enables reading multi-volume non-tape mediums like CDROMs.
-X filelist
Read list of files to be listed or extracted from the text file
filelist in addition to those specified on the command line.
This can be used in conjunction with the -t or -x commands. The
file filelist should contain file names separated by newlines.
filelist may be an ordinary file or - (the standard input).
-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 con-
tinue.
(The 4.3BSD option syntax is implemented for backward compatibility
but is not documented here.)
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.
: 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 , 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.
Incremental dump too low
When doing an 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 an 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
Tape read error while skipping over inode
Tape read error while trying to resynchronize
A tape (or other media) read error has occurred. If a file name
is specified, its contents are probably partially wrong. If an
inode is being skipped or the tape is trying to resynchronize,
no extracted files have been corrupted, though files may not be
found on the tape.
resync restore, skipped blocks
After a dump read error, restore may have to resynchronize
itself. This message lists the number of blocks that were
skipped over.
EXIT STATUS
Restore exits with zero status on success. Tape errors are indicated
with an exit code of 1.
When doing a comparison of files from a dump, an exit code of 2 indi-
cates that some files were modified or deleted since the dump was
made.
ENVIRONMENT
If the following environment variable exists it will be utilized by
restore:
TAPE If no -f option was specified, restore will use the device
specified via TAPE as the dump device. TAPE may be of the form
tapename, host:tapename or user@host:tapename.
TMPDIR The directory given in TMPDIR will be used instead of /tmp to
store temporary files.
RMT The environment variable RMT will be used to determine the
pathname of the remote rmt(8) program.
RSH Restore uses the contents of this variable to determine the
name of the remote shell command to use when doing a network
restore (rsh, ssh etc.). If this variable is not set, rcmd(3)
will be used, but only root will be able to do a network
restore.
FILES
/dev/st0
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), mount(8), mke2fs(8), rmt(8)
BUGS
Restore can get confused when doing incremental restores from dumps
that were made on active file systems.
A level 0 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 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 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 differ-
ent dumps started at the same time, and separate operations shouldn't
conflict with each other.
To do a network restore, you have to run restore as root or use a
remote shell replacement (see RSH variable). This is due to the pre-
vious security history of dump and restore. ( restore is written to
be setuid root, but we are not certain all bugs are gone from the code
- run setuid at your own risk.)
At the end of restores in -i or -x modes (unless -o option is in use),
restore will ask the operator whether to set the permissions on the
current directory. If the operator confirms this action, the permis-
sions on the directory from where restore was launched will be
replaced by the permissions on the dumped root inode. Although this
behaviour is not really a bug, it has proven itself to be confusing
for many users, so it is recommended to answer 'no', unless you're
performing a full restore and you do want to restore the permissions
on '/'.
It should be underlined that because it runs in user code, restore ,
when run with the -C option, sees the files as the kernel presents
them, whereas dump sees all the files on a given filesystem. In par-
ticular, this can cause some confusion when comparing a dumped
filesystem a part of which is hidden by a filesystem mounted on top of
it.
AUTHOR
The dump/restore backup suite was ported to Linux's Second Extended
File System by Remy Card . He maintained the ini-
tial versions of dump (up and including 0.4b4, released in january
1997).
Starting with 0.4b5, the new maintainer is Stelian Pop
.
AVAILABILITY
The dump/restore backup suite is available from
HISTORY
The restore command appeared in 4.2BSD.
BSD version 0.4b39 of January 21, 2005 RESTORE(8)
UNIX/Linux commands referenced on this page: