restor.8

UNIX v6源代码 这几乎是最经典的unix版本 unix操作系统设计和莱昂氏unix源代码分析都是用的该版

.th RESTOR VIII 11/24/73
.sh NAME
restor \*- incremental file system restore
.sh SYNOPSIS
.bd restor
key [ arguments ]
.sh DESCRIPTION
.it Restor
is used to read magtapes dumped with the
.it dump
command.
The
.it key
argument specifies what is to be done.
.it Key
is a character from the set
.bd trxw.
.s3
.lp +5 3
\fBt\fR	The date that the tape was made and the date that
was specified in the
.it dump
command are printed.
A list of all of the i-numbers on the tape
is also given.
.s3
.lp +5 3
\fBr\fR	The tape
is read and loaded into the file system
specified in
.it arguments.
This should not be done lightly (see below).
.s3
.lp +5 3
\fBx\fR	Each file on the
tape is individually extracted into
a file whose name is the file's i-number.
If
there are
.it arguments,
they are interpreted as i-numbers and only they are
extracted.
.s3
.lp +5 3
\fBc\fR	If the tape overflows, increment the last character
of its name and continue on that drive.
(Normally it asks you to change tapes.)
.s3
.lp +5 3
\fBf\fR	Read the dump from the next argument file
instead of the tape.
.s3
.lp +5 3
\fBi\fR	All read and checksum errors
are reported, but will not
cause termination.
.s3
.lp +5 3
\fBw\fR	In conjunction with the
.bd x
option,
before each file is extracted,
its i-number is typed out.
To extract this file,
you must respond with
.bd y.
.s3
.i0
The
.bd x
option is used to retrieve individual files.
If the i-number of the desired file is not known,
it can be discovered by following the file system
directory search algorithm.
First retrieve the
.it root
directory whose i-number is 1.
List this file with
.it "ls \*-fi 1."
This will give names and i-numbers of
sub-directories.
Iterating, any file may be retrieved.
.s3
The
.bd r
option should only be used to restore
a complete dump tape onto a clear file system
or to restore an incremental dump tape onto this.
Thus
.s3
	/etc/mkfs /dev/rp0 40600
.br
	restor r /dev/rp0
.s3
is a typical sequence to restore a complete dump.
Another
.it restor
can be done to get an incremental dump
in on top of this.
.s3
A
.it dump
followed by a
.it mkfs
and a
.it restor
is used to
change the size of a file system.
.sh FILES
/dev/mt0
.sh "SEE ALSO"
ls (I), dump (VIII), mkfs (VIII), clri (VIII)
.sh DIAGNOSTICS
There are various diagnostics
involved with reading the tape and writing the disk.
There are also diagnostics if the i-list or the free list
of the file system is not large enough to hold the dump.
.s3
If the dump extends over more than one tape,
it may ask you to change tapes.
Reply with a new-line when the next tape has been mounted.
.sh BUGS
There is redundant information on the tape
that could be used in case of tape reading problems.
Unfortunately,
.it restor's
approach is to exit if anything is wrong.