RESTORE(8)

NAME
restore, rrestore - incremental file system restore

SYNOPSIS
/sbin/restore key [argument ... ] [ name ... ]

DESCRIPTION

Restore reads tapes dumped with the dump(8) command. Its actions are controlled by the key argument. The key is a string of characters containing at most one function letter and possibly one or more function modifiers. Those key characters which take an argument take them sequentially in the order of the characters from the argument list supplied. The name arguments to the command are file or directory names specifying the files that are to be restored. Unless the h key is specified (see below), the appearance of a directory name refers to the files and (recursively) subdirectories of that directory.

The function portion of the key is specified by one of the following letters:

t   The names of the specified files are listed if they occur on the tape. If no name argument is given, then the root directory is listed, which results in the entire content of the tape being listed, unless the h key has been specified. Note that the t key replaces the function of the old dumpdir program.

x   The named files are extracted from the tape. If the named file matches a directory whose contents had been written onto the tape, and the h key is not specified, the directory is recursively extracted. The owner, modification time, and mode are restored (if possible). If no name argument is given, then the root directory is extracted, which results in the entire content of the tape being extracted, unless the h key has been specified.

i   This mode allows interactive restoration of files from a dump tape. After reading in the directory information from the tape, 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.

    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 key is set the inode number of each entry is also listed.

    cd arg - Change the current working directory to the specified argument.

    pwd - Print the full pathname of the current working 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 key is specified on the command line). Files that are on the extraction list are prepended with a ``*'' when they are listed by ls.

    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 key 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 tape. 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.

    setmodes - All the directories that have been added to the extraction list have their owner, modes, and times set; nothing is extracted from the tape. This is useful for cleaning up after a restore has been prematurely aborted.

    verbose - The sense of the v key is toggled. When set, the verbose key 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.

    force - The sense of the F key is toggled. When set, the force key causes restore to force the files and directories extracted onto the disc if possible. See the description for the F key below.

    help - List a summary of the available commands.

    quit - Restore immediately exits, even if the extraction list is not empty.

r   The tape is read and loaded into the current directory. This should not be done lightly since each file is restored onto the filesystem with the same inode number that it had when dumped to tape; the r key should only be used to restore a complete dump tape onto a clear file system or to restore an incremental dump tape after a full level zero restore. Thus

        newfs /dev/rsd1a CONNER
        mount /dev/rsd1a /mnt
        cd /mnt
        restore r

    is a typical sequence to restore a complete dump. Another restore can be done to get an incremental dump in on top of this. Note that restore leaves a file restoresymtab in the root directory to pass information between incremental restore passes. This file should be removed when the last incremental tape has been restored.
    A dump(8) followed by a newfs(8) and a restore is used to change the size of a file system.

R   Restore requests a particular tape of a multi volume set on which to restart a full restore (see the r key above). This allows restore to be interrupted and then restarted.

The following characters may be used in addition to the letter that selects the function desired.

f   The next argument to restore is used as the name of the archive instead of /dev/tape. 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 -)
    The name is processed by sprintf(3) before use so that if it contains ``%d'' then a unique name (with the ``%d'' replaced by the tape number) for each `tape' is produced.
    e.g. restore f TAPE-%02d would access `tape' names TAPE-01, TAPE-02, TAPE-03, ...
    If the name of the file is of the form machine:device the restore is done from the specified machine over the network using rmt(8C). Since restore is normally run by root, the name of the local machine must appear in the .rhosts file of the remote machine. If the file is specified as user@machine:device, restore will attempt to execute as the specified user on the remote machine. The specified user must have a .rhosts file on the remote machine that allows root from the local machine. If restore is called as rrestore, the tape defaults to dumphost:/dev/tape. To direct the input from a desired remote machine, set up an alias for dumphost in the file /etc/hosts.

v   Normally restore does its work silently. The v (verbose) key causes it to type the name of each file it treats preceded by its file type.

F   When used in conjunction with x or i this key causes restore to force the files and directories extracted onto the disc if possible. It breaks links, deletes files or directories before replacing with the tape copy, and restores all modes to those of the files and directories extracted from the tape. It produces very few warning messages when in force mode.

b   The next argument to restore is used as the block size of the tape (in kilobytes). If the -b option is not specified, restore tries to determine the tape block size dynamically.

y   Restore will not ask whether it should abort the restore if gets a tape error. It will always try to skip over the bad tape block(s) and continue as best it can.

m   Restore will 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. Files should be specified by name on the command line but will be restored into the current directory with a new name which is the inode number of the file as it was dumped.

h   Restore extracts the actual directory, rather than the files that it references. This prevents hierarchical restoration of complete subtrees from the tape.

s   The next argument to restore is a number which selects the file on a multi-file dump tape. File numbering starts at 1.

DIAGNOSTICS
Complaints about bad key characters.

Complaints if it gets a read error. If y has been specified, or the user responds ``y'', restore will attempt to continue the restore.

If the dump extends over more than one tape, restore will ask the user to change tapes. If the x or i key 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 tape created on an active file system.

Incremental tape too low
    When doing incremental restore, a tape that was written before the previous incremental tape, or that has too low an incremental level has been loaded.

Incremental tape too high
    When doing incremental restore, a tape that does not begin its coverage where the previous incremental tape 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 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 tape read error, restore may have to resynchronize itself. This message lists the number of blocks that were skipped over.

FILES
/dev/tape		default tape unit to restore from.
dumphost:/dev/tape	default tape unit if called as rrestore.
/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
rrestore(8C) dump(8), newfs(8), mount(8), mkfs(8)

BUGS
Restore can get confused when doing incremental restores from dump tapes that were made on active file systems.

A level zero dump must be done after a full restore. Because restore runs in user code, it has no control over inode allocation; thus a full restore must be done to get a new set of directories reflecting the new inode numbering, even though the contents of the files is unchanged.

In its messages Restore always refers to tape even when the restore is being done from a disc file, floppy disc, or other removeable media.