NAME

dump − incremental file system dump

SYNOPSIS

/etc/dump [ key [ argument ... ] file system ]

DESCRIPTION

Dump copies to magnetic tape all files changed after a certain date in the file system.  The key specifies the date and other options about the dump.  Key consists of characters from the set 0123456789bcdfnsuW. 

0−9 Sets the dump level to this number.  Dumps all files modified since the last date stored in the file /etc/dumpdates for the same file system at lesser levels.  If no date is determined by the level, the beginning of time is assumed; thus the option 0 causes the entire file system to be dumped. 

b Tells dump to use the next argument as the blocking factor for tape records. The default blocking factor is 20 (the maximum).  Use this option only with raw magnetic tape archives.  The block size is determined automatically when reading tapes. 

c Identifies the dump tape as an ISI cartridge—by default, a Scotch 300XL™ cartridge.  Note that you can use the s key to set the tape length in feet. 

d Specifies the density of the tape, expressed in BPI, as the next argument.  The density is used to calculate the amount of tape used per reel.  The default tape density is 1600 BPI. 

f Places the dump on the next argument file instead of the tape.  If the name of the file is “−”, dump writes to standard output. 

n Whenever dump requires operator attention, notifies by means similar to a wall(1) all of the operators in the group “operator”. 

s Specifies the size of the dump tape in feet.  The number of feet is taken from the next argument.  When the specified size is reached, dump waits for reels to be changed.  The default tape size is 2300 feet. 

u If the dump completes successfully, writes the date of the beginning of the dump on file /etc/dumpdates.  This file records a separate date for each file system and each dump level.  Users can read /etc/dumpdates.  The file consists of one free format record per line:  file system name, increment level, and ctime(3) format dump date.  /etc/dumpdates may be edited to change any of the fields, if necessary. 

W Tells the operator which file systems need to be dumped.  With this option, dump reads the files /etc/dumpdates and /etc/fstab, then, for each file system in /etc/dumpdates, it prints the most recent dump date and level and indicates which file systems should be dumped.  Setting the W option invalidates all other options.  Once dump has printed the dump history, it exits. 

w Gathers dump information like W, but prints only those file systems which need to be dumped. 

If no arguments are given, the key is assumed to be 9u and a default file system is dumped to the default tape. 

Dump requires operator intervention when any of the following occur:

•  dump reaches the end of a tape
•  dump completes its copy
•  dump encounters a tape write error
•  dump encounters a tape open error
•  dump encounters more than 32 disk read errors

If the operator invoked dump with the n key, dump will notify all users in the group "operator" when any of these errors occur.  An operator must use the control terminal (the terminal used to begin the dump) to interact with dump.  The operator should type “yes” or “no,” to answer the questions dump prints on the screen. 

Since performing a full dump involves a lot of time and effort, dump checkpoints itself at the start of each tape volume.  If for any reason dump fails while writing that volume, dump will, with operator permission, restart itself from the checkpoint after the old tape has been rewound and removed and a new tape has been mounted. 

At periodic intervals, dump prints messages that include low estimates of the number of blocks to write, the number of tapes the dump will need, and the time remaining until dump complete.  It also tells the operator when to change the tape.  By printing verbose messages, dump lets other users know that the terminal controlling the dump is busy and that the dump is continuing. 

To keep your dump tapes up to date, run the dump program according to this schedule.  Start with a full level 0 dump

dump 0un

Next, run dumps of active file systems on a daily basis using a modified Tower of Hanoi algorithm with this sequence of dump levels:

3 2 5 4 7 6 9 8 9 9 ... 

For the daily dumps, use a set of 10 tapes per dumped file system on a cyclical basis. Each week, perform a level 1 dump and repeat the daily Hanoi sequence with 3 tapes. For weekly dumps, use a set of 5 tapes per dumped file system, also on a cyclical basis. Each month, perform a level 0 dump on a set of fresh tapes for permanent storage.

FILES

/dev/rrp1gdefault file system to dump from
/dev/rmt8default tape unit to dump to
/etc/dumpdatesnew format dump date record
/etc/fstabdump table: file systems and frequency
/etc/groupto find group operator

SEE ALSO

restore(8), dump(5), fstab(5)

DIAGNOSTICS

The dump program includes many verbose diagnostic messages.  As many of these messages are self-explanatory, this man page describes only the dump program’s exit codes. 

If dump successfully completes its copy, it exits with zero status.  Dump indicates startup errors with an exit code of 1 and abnormal termination with an exit code of 3. 

BUGS

If there are fewer than 32 read errors, dump ignores them and continues its copying. 

Each reel requires a new process.  Consequently, parent processes for reels already written do not terminate until the entire tape is written. 

Running dump with the W or w option does not report file systems that have never been recorded in /etc/dumpdates, even if such file system are listed in /etc/fstab. 

Unfortunately, the dump program does not know about the dump sequence, does not keep track of scribbled on tapes, and does not tell the operator which tape to mount and when it should be mounted.  Also, the program does not provide enough assistance to the operator running restore. 
 

4th Berkeley Distribution  —  October 27, 1987