restore ? restore files or file systems from backups made with dump

restore ?C [?ckMvy] [?b blocksize] [?D filesystem] [?f file] [?s fileno] [?T directory]

restore ?i [?chkmMNuvy] [?b blocksize] [?f file] [?s fileno] [?T directory]

restore ?R [?ckMNuvy] [?b blocksize] [?f file] [?s fileno] [?T directory]

restore ?r [?ckMNuvy] [?b blocksize] [?f file] [?s fileno] [?T directory]

restore ?t [?chkMNuvy] [?b blocksize] [?f file] [?s fileno] [?T directory] [?X filelist] [file ...]

restore ?x [?chkmMNuvy] [?b blocksize] [?f 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 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:

?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 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’ 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 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.

?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:

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.

?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:

?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 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).

?k’ Use Kerberos authentication when contacting the remote tape server. (Only available if this options was enabled when restore was compiled.)

?h’ Extract the actual directory, rather than the files that it references. This prevents hierarchical restoration of complete subtrees from the dump.

?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 only print file names. Files are not extracted.

?s fileno
Read from the specified fileno on a multi-file tape. File numbering 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 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.

?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.

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:

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

/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)

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 restore code - run setuid at your own risk.)

The dump/restore backup suit 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
<pop@cybercable.fr>.

The dump/restore backup suit is available from
http://dump.sourceforge.net

The restore command appeared in 4.2BSD.

restore 0.4b19 August 20, 2000 restore 0.4b19