NAME

dump − A program that dumps directories

SYNOPSIS

dump [options] directory

OPTIONS

−a Reset access times after dumping each file. 

−f  filenameUse filename as the name of the dump archive. 

−help Print a help message. 

−i number Initialize the tape, using number for the label. 

−l  digitThe single digit in the range 0-9 specifies the dump level.  The default is zero. 

−m usernameSend mail to username to report a fatal error, or successful completion. 

−rRe-initialize the tape.  Any data on the tape is lost. 

−sSafe re-initialization of tape.  The reinitialization will fail if the tape has been recently used. 

−t Print the dump archive table of contents. 

−v Verbose.  The name of each file is listed as it is dumped. 

−u Unofficial dump.  The dump is not recorded in the dumpdates file. 
 

INTRODUCTION

The dump 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 dump -l 2 -f /dev/tape0 /sprite
 
will dump all files in the directory /sprite in tar format, to /dev/tape0. 

TAPE FORMAT

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 label 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 SPRITE DUMP TAPE, Version v Level x Tape n
 
where v is the version of dump that wrote the tape, x is the level of the dump tape, and n is the dump tape number.  The version is intended to allow future versions of dump to be backwards compatible.  The level is filled in when the tape is initialized, but is otherwise unused.  It could be used by dump and higher-level software to automate the dumping process. 

Subsequent lines in the tape label contain a table of contents for the tape, and are of the form TapeNum FileNum MBDumped MBLeft Date FileSystem
 
where TapeNum is the tape number, FileNum is the file number on tape corresponding to the current entry (starting with 1), MBDumped is the number of MBytes dumped from the filesystem, MBLeft is the number of MBytes remaining on the tape after the filesystem was dumped, Date is the date when the filesystem was dumped, and FileSystem is the name of the filesystem that was dumped. 

FILES

/sprite/admin/dump/dumpdates
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 TapeNum FileNum MBDumped MBLeft Date FileSystem where TapeNum is the tape number, FileNum is the file number on tape corresponding to the current entry (starting with 1), MBDumped is the number of MBytes dumped from the filesystem, MBLeft is the number of MBytes remaining on the tape after the filesystem was dumped, Date is the date when the filesystem was dumped, and FileSystem is the name of the filesystem that was dumped. 

/sprite/admin/dump/dumplog
This file contains low-level debugging information that is printed out by dump as it runs. 

/sprite/admin/dump/statuslog
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 DriveType Serial TapeNum MBDumped ErrorRate Date Device DriveType is the type of drive that was used (e.g. EXB-8500).  Serial is the serial number of the drive.  The combination of the drive type and serial number should allow tape drives to be uniquely identified.  TapeNumber is the number of the tape that was used.  MBDumped is the number of MBytes that were dumped.  ErrorRate 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 Date is the date on which the dump occurred, and the Device is the name of the device as passed to the dump 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. 

KEYWORDS

dump, restore, tape, backup, tar
 

Sprite version 1.0  —  November 22, 1991