rrestore
RESTORE(8) BSD System Manager's Manual RESTORE(8)
NAME
restore - restore files or file systems from backups made with dump
SYNOPSIS
restore -C [-cklMvVy] [-b blocksize] [-D filesystem] [-f file]
[-F script] [-L limit] [-s fileno] [-T directory]
restore -i [-achklmMNuvVy] [-A file] [-b blocksize] [-f file] [-F script]
[-Q file] [-s fileno] [-T directory]
restore -P file [-achklmMNuvVy] [-A file] [-b blocksize] [-f file]
[-F script] [-s fileno] [-T directory] [-X filelist] [file ...]
restore -R [-cklMNuvVy] [-b blocksize] [-f file] [-F script] [-s fileno]
[-T directory]
restore -r [-cklMNuvVy] [-b blocksize] [-f file] [-F script] [-s fileno]
[-T directory]
restore -t [-chklMNuvVy] [-A file] [-b blocksize] [-f file] [-F script]
[-Q file] [-s fileno] [-T directory] [-X filelist] [file ...]
restore -x [-achklmMNuvVy] [-A file] [-b blocksize] [-f file] [-F script]
[-Q file] [-s fileno] [-T directory] [-X filelist] [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 back-
ups 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 com-
mand 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 descen-
dents 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 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 direc-
tory.
quit Restore immediately exits, even if the extraction
list is not empty.
setmodes All directories that have been added to the extrac-
tion 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.
-P file
Restore creates a new Quick File Access file file from an exist-
ing 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 use-
ful 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 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 (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.
The following additional options may be specified:
-a In -i or -x mode, restore does ask the user for the volume number
on which the files to be extracted are supposed to be (in order
to minimise the time be reading only the interesting volumes).
The -a option disables this behaviour and reads all the volumes
starting with 1. This option is useful when the operator 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 inter-
active 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 dynam-
ically.
-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 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 ref-
erences. This prevents hierarchical restoration of complete sub-
trees 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 <prefix>001,
<prefix>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.
-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 man page, option MTSETDRVBUFFER, or the mt man
page, on how to set the driver to return logical 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 dur-
ing 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 filesys-
tem, 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 directory.
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 continue.
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 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 <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, 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 <num> blocks
After a dump read error, restore may have to resynchronize
itself. This message lists the number of blocks that were
skipped over.
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 indicates
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 speci-
fied 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 path-
name 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 different 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 previous secu-
rity 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.)
AUTHOR
The dump/restore backup suite was ported to Linux's Second Extended File
System by Remy Card <card@Linux.EU.Org>. He maintained the initial ver-
sions of dump (up and including 0.4b4, released in january 1997).
Starting with 0.4b5, the new maintainer is Stelian Pop
<stelian@popies.net>.
AVAILABILITY
The dump/restore backup suite is available from
http://dump.sourceforge.net
HISTORY
The restore command appeared in 4.2BSD.
restore 0.4b28 April 12, 2002 restore 0.4b28
