1.\" Copyright (c) 1980, 1991 Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" %sccs.include.redist.man% 5.\" 6.\" @(#)dump.8 6.6 (Berkeley) 03/16/91 7.\" 8.Dd 9.Dt DUMP 8 10.Os BSD 4 11.Sh NAME 12.Nm dump 13.Nd filesystem backup 14.Sh SYNOPSIS 15.Nm dump 16.Op Cm 0123456789fusdWn Op Ar argument ... 17.Op Ar filesystem 18.Sh DESCRIPTION 19.Nm Dump 20examines files 21on a filesystem 22and determines which files 23need to be backed up. These files 24are copied to the given disk, tape or other 25storage medium for safe keeping (see 26.Xr rdump 8 27for 28remote backups) . 29.Pp 30The following options are supported by 31.Nm dump: 32.Bl -tag -width 4n 33.It Cm 0\-9 34Dump levels. 35A level 0, full backup, 36guarantees the entire file system is copied. 37A level number above 0, 38incremental backup, 39tells dump to 40copy all files new or modified since the 41last dump of the same or lower level. The default 42level is 9. 43.It Cm f Op Ar file 44Write the backup to 45.Ar file ; 46.Ar file 47may be a special device file 48like 49.Pa /dev/rmt12 50(a tape drive), 51.Pa /dev/rsd1c 52(an optical drive), 53an ordinary file, 54or 55.Ql Fl 56(the standard output). 57.It Cm d Ar density 58Set tape density to 59.Ar density . 60The default is 1600BPI. 61.It Cm n 62Whenever 63.Nm dump 64requires operator attention, 65notify all operators in the group 66.Dq operator 67by means similar to a 68.Xr wall 1 . 69.It Cm s Ar feet 70Attempt to caluculate the amount of tape needed 71at a particular density. 72If this amount is exceeded, 73.Nm dump 74prompts for a new tape. It is recommended to be a bit conservative 75on this option. 76The default size is 2300 feet. 77.It Cm u 78Update the file 79.Pa /etc/dumpdates 80after a successful dump. 81The format of 82.Pa /etc/dumpdates 83is readable by people, consisting of one 84free format record per line: 85filesystem name, 86increment level 87and 88.Xr ctime 3 89format dump date. 90There may be only one entry per filesystem at each level. 91The file 92.Pa /etc/dumpdates 93may be edited to change any of the fields, 94if necessary. 95.It Cm W 96.Nm Dump 97tells the operator what file systems need to be dumped. 98This information is gleaned from the files 99.Pa /etc/dumpdates 100and 101.Pa /etc/fstab . 102The 103.Cm W 104option causes 105.Nm dump 106to print out, for each file system in 107.Pa /etc/dumpdates 108the most recent dump date and level, 109and highlights those file systems that should be dumped. 110If the 111.Cm W 112option is set, all other options are ignored, and 113.Nm dump 114exits immediately. 115.It Cm w 116Is like W, but prints only those filesystems which need to be dumped. 117.El 118.Pp 119If no options are specified, 120.Nm dump 121does a level 122.Cm 9u 123to the system's default tape device. 124.Pp 125.Nm Dump 126requires operator intervention on these conditions: 127end of tape, 128end of dump, 129tape write error, 130tape open error or 131disk read error (if there are more than a threshold of 32). 132In addition to alerting all operators implied by the 133.Cm n 134key, 135.Nm dump 136interacts with the operator on 137.Em dump's 138control terminal at times when 139.Nm dump 140can no longer proceed, 141or if something is grossly wrong. 142All questions 143.Nm dump 144poses 145.Em must 146be answered by typing \*(lqyes\*(rq or \*(lqno\*(rq, 147appropriately. 148.Pp 149Since making a dump involves a lot of time and effort for full dumps, 150.Nm dump 151checkpoints itself at the start of each tape volume. 152If writing that volume fails for some reason, 153.Nm dump 154will, 155with operator permission, 156restart itself from the checkpoint 157after the old tape has been rewound and removed, 158and a new tape has been mounted. 159.Pp 160.Nm Dump 161tells the operator what is going on at periodic intervals, 162including usually low estimates of the number of blocks to write, 163the number of tapes it will take, the time to completion, and 164the time to the tape change. 165The output is verbose, 166so that others know that the terminal 167controlling 168.Nm dump 169is busy, 170and will be for some time. 171.Pp 172In the event of a catastrophic disk event, the time required 173to restore all the necessary backup tapes or files to disk 174can be kept to a minimum by staggering the incremental dumps. 175An efficient method of staggering incremental dumps 176to minimize the number of tapes follows: 177.Bl -bullet -offset indent 178.It 179Always start with a level 0 backup, for example: 180.Bd -literal -offset indent 181/etc/dump 0ufds /dev/nrst1 54000 6000 /usr/src 182.Ed 183.Pp 184This should be done at set intervals, say once a month or once every two months, 185and on a set of fresh tapes that is saved forever. 186.It 187After a level 0, dumps of active file 188systems are taken on a daily basis, 189using a modified Tower of Hanoi algorithm, 190with this sequence of dump levels: 191.Bd -literal -offset indent 1923 2 5 4 7 6 9 8 9 9 ... 193.Ed 194.Pp 195For the daily dumps, it should be possible to use a fixed number of tapes 196for each day, used on a weekly basis. 197Each week, a level 1 dump is taken, and 198the daily Hanoi sequence repeats beginning with 3. 199For weekly dumps, another fixed set of tapes per dumped file system is 200used, also on a cyclical basis. 201.El 202.Pp 203After several months or so, the daily and weekly tapes should get 204rotated out of the dump cycle and fresh tapes brought in. 205.Sh FILES 206.Bl -tag -width /etc/dumpdates -compact 207.It Pa /dev/rrp1g 208default filesystem to dump from (system dependent). 209.It Pa /dev/rmt8 210default tape unit to dump to 211.It Pa /etc/dumpdates 212new format dump date record 213.It Pa /etc/fstab 214dump table: file systems and frequency 215.It Pa /etc/group 216to find group 217.Em operator 218.El 219.Sh SEE ALSO 220.Xr rdump 8 , 221.Xr restore 8 , 222.Xr dump 5 , 223.Xr fstab 5 224.Sh DIAGNOSTICS 225Many, and verbose. 226.Pp 227Dump exits with zero status on success. 228Startup errors are indicated with an exit code of 1; 229abnormal termination is indicated with an exit code of 3. 230.Sh BUGS 231.Pp 232Fewer than 32 read errors on the filesystem are ignored. 233Each reel requires a new process, so parent processes for 234reels already written just hang around until the entire tape 235is written. 236.Pp 237.Nm Dump 238with the 239.Cm W 240or 241.Cm w 242options does not report filesystems that have never been recorded 243in 244.Pa /etc/dumpdates , 245even if listed in 246.Pa /etc/fstab . 247.Pp 248It would be nice if 249.Nm dump 250knew about the dump sequence, 251kept track of the tapes scribbled on, 252told the operator which tape to mount when, 253and provided more assistance 254for the operator running 255.Xr restore . 256.Sh HISTORY 257A 258.Nm 259command appeared in Version 6 AT&T UNIX. 260