RESTORE(8) System management commands RESTORE(8)
restore - restore files or file systems from backups made with dump
restore -C [-cdHklMvVy] [-b blocksize] [-D filesystem] [-f file] [-F script] [-L limit] [-s fileno] [-T directory]
restore -i [-acdhHklmMNouvVy] [-A file] [-b blocksize] [-f file] [-F script] [-Q file] [-s fileno] [-T directory]
restore -P file [-acdhHklmMNuvVy] [-b blocksize] [-f file] [-F script] [-s fileno] [-T directory] [-X filelist] [ file ... ]
restore -R [-cdHklMNuvVy] [-b blocksize] [-f file] [-F script] [-s fileno] [-T directory]
restore -r [-cdHklMNuvVy] [-b blocksize] [-f file] [-F script] [-s fileno] [-T directory]
restore -t [-cdhHklMNuvVy] [-A file] [-b blocksize] [-f file] [-F script] [-Q file] [-s fileno] [-T directory] [-X filelist] [ file ... ]
restore -x [-adchHklmMNouvVy] [-A file] [-b blocksize] [-f file] [-F script] [-Q file] [-s fileno] [-T directory] [-X filelist] [ file ...
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.
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 avail-
able 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 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.
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.
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.
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 Restore immediately exits, even if the extraction list is not empty.
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.
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.
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 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:
mount /dev/sda1 /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 possible). 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 by 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 interactive mode.
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.
The number of kilobytes per dump record. If the -b option is not specified, restore tries to determine the media block size dynami-
-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.
The -D flag allows the user to specify the filesystem name when using restore with the -C option to check the backup.
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).
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.
Use a hashtable having the specified number of entries for storing the directories entries instead of a linked list. This hashtable
will considerably speed up inode lookups (visible especially in interactive mode when adding/removing files from the restore list),
but at the price of much more memory usage. The default value is 1, meaning no hashtable is used.
-k Use Kerberos authentication when contacting the remote tape server. (Only available if this options was enabled when restore was
-l When doing remote restores, assume the remote file is a regular file (instead of a tape device). If you're restoring a remote com-
pressed file, you will need to specify this option or restore will fail to access it correctly.
The -L flag allows the user to specify a maximal number of miscompares 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 useful 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.
-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.
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 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 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.
Read from the specified fileno on a multi-file tape. File numbering starts at 1.
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 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
-V Enables reading multi-volume non-tape mediums like CDROMs.
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.
(The 4.3BSD option syntax is implemented for backward compatibility but is not documented here.)
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
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.
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.
the default tape drive
file containing directories on the tape
owner, mode, and time stamps for directories
information passed between incremental restores
dump(8), mount(8), mke2fs(8), rmt(8)
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
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 permissions 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 particular, this can cause some confusion when comparing a dumped filesys-
tem a part of which is hidden by a filesystem mounted on top of it.
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
versions of dump (up and including 0.4b4, released in January 1997).
Starting with 0.4b5, the new maintainer is Stelian Pop <email@example.com>.
The dump/restore backup suite is available from <http://dump.sourceforge.net>
The restore command appeared in 4.2BSD.
version 0.4b44 of June 10, 2011 RESTORE(8)