Sprite 1984 - 1993/Sprite 1984 - 1993.iso/src/cmds/dump/dump.man

Text File | 1991-11-22 | 5KB | 139 lines

' $Header: /sprite/src/admin/dump/RCS/dump.man,v 1.4 91/11/22 14:09:23 jhh Exp $ SPRITE (Berkeley)
.so \*(]ltmac.sprite
.HS DUMP cmds
.BS
.SH NAME
dump \- A program that dumps directories
.SH SYNOPSIS
\fBdump\fR [\fIoptions\fR] \fIdirectory\fR
.SH OPTIONS
.IP "\fB\-a \fR" 15
Reset access times after dumping each file.
.IP "\fB\-f  \fIfilename\fR" 15
Use \fIfilename\fR as the name of the dump archive.
.IP "\fB\-help \fR" 15
Print a help message.
.IP "\fB\-i number \fR" 15
Initialize the tape, using \fBnumber\fR for the label.
.IP "\fB\-l  \fIdigit\fR" 15
The single digit in the range 0-9 specifies the dump level.  The default
is zero.
.IP "\fB\-m \fIusername\fR" 15
Send mail to \fIusername\fR to report a fatal error, or successful completion.
.IP "\fB\-r\fR" 15
Re-initialize the tape.  Any data on the tape is lost.
.IP "\fB\-s\fR" 15
Safe re-initialization of tape.  The reinitialization will fail if the
tape has been recently used.
.IP "\fB\-t \fR" 15
Print the dump archive table of contents.
.IP "\fB\-v \fR" 15
Verbose.  The name of each file is listed as it is dumped.
.IP "\fB\-u \fR" 15
Unofficial dump.  The dump is not recorded in the dumpdates file.
.BE

.SH INTRODUCTION
.PP
The \fBdump\fR command is used to do an incremental dump of a
set of directory.  It will recursively dump all files and
subdirectories.  Each file that has been created or modified
since the last lower level dump will
be copied to the archive file.  For example, the command
.DS
dump -l 2 -f /dev/tape0 /sprite

.DE
will dump all files in the directory \fB/sprite\fR
in tar format, to \fB/dev/tape0\fR.
.SH TAPE FORMAT
.PP
Dump tapes have a particular format. It is assumed that blocks on the
tape cannot be overwritten, so the tape is written in an append-only fashion.
When a tape is initialized a file called the tape \fIlabel\fP is written
at the beginning of the tape.
Each time a filesystem is dumped a new updated tape label is written to
the end of the tape, so that the current tape label is always the last
one on the tape.
The tape label is 16 Kbytes in size, and
consists of a sequence of ASCII strings separated by newlines.  The
first string is of the form
.DS
SPRITE DUMP TAPE, Version \fIv\fP Level \fIx\fP Tape \fIn\fP

.DE
where \fIv\fP is the version of \fBdump\fP that wrote the tape,
\fBx\fP is the level of the dump tape, and \fBn\fP is the dump tape number.
The version is intended to allow future versions of \fBdump\fP to be
backwards compatible.
The level is filled in when the tape is initialized, but is otherwise
unused.  It could be used by \fBdump\fP and higher-level software to
automate the dumping process.
.PP
Subsequent lines in the tape label contain a table of contents for the tape,
and are of the form
.DS
\fITapeNum FileNum MBDumped MBLeft Date FileSystem\fP

.DE
where \fITapeNum\fP is the tape number, \fIFileNum\fP is the file number
on tape corresponding to the current entry (starting with 1),
\fIMBDumped\fP is the number of MBytes dumped from the filesystem,
\fIMBLeft\fP is the number of MBytes remaining on the tape after
the filesystem was dumped, \fIDate\fP is the date when the filesystem was
dumped, and \fIFileSystem\fP
is the name of the filesystem that was dumped.
.SH FILES
.TP
\fB/sprite/admin/dump/dumpdates\fP
When a dump completes the information that is written into the tape label
is also written into this file.
Each line is of the form
.sp
\fITapeNum FileNum MBDumped MBLeft Date FileSystem\fP
.sp
.SP
where \fITapeNum\fP is the tape number, \fIFileNum\fP is the file number
on tape corresponding to the current entry (starting with 1),
\fIMBDumped\fP is the number of MBytes dumped from the filesystem,
\fIMBLeft\fP is the number of MBytes remaining on the tape after
the filesystem was dumped, \fIDate\fP is the date when the filesystem was
dumped, and \fIFileSystem\fP
is the name of the filesystem that was dumped.
.TP
\fB/sprite/admin/dump/dumplog\fP
This file contains low-level debugging information that is printed out by
\fBdump\fP as it runs.
.TP
\fB/sprite/admin/dump/statuslog\fP
This file contains information about the status of both the tape drives
and the tapes.
A line is added to the file each time a dump completes, and is of the form
.sp
\fIDriveType Serial TapeNum MBDumped ErrorRate Date Device\fP
.sp
.SP
\fIDriveType\fP is the type of drive that was used (e.g. EXB-8500).
\fISerial\fP is the serial number of the drive.
The combination of the drive type
and serial number should allow tape drives to be uniquely identified.
\fITapeNumber\fP is the number of the tape that was used.
\fIMBDumped\fP is the number of MBytes that were dumped.
\fIErrorRate\fP is the number of errors per tape access, expressed as
a percentage of tape accesses.
An error rate of 100% means that there was an average of one error per
tape access.
The definition of an error is vendor specific
but an increase in the error rate over time may indicate that a tape is
wearing out or that a drive needs servicing.
The \fIDate\fP is the date on which the dump occurred,
and the \fIDevice\fP is the name of the device as passed to the
\fBdump\fP command.
The latter should not be considered to uniquely identify a tape drive
since the mapping between the device name and the device can change,
thus the drive type and serial number should be used to look for
an increasing error rate on a particular drive.
.SH KEYWORDS
dump, restore, tape, backup, tar