1.\" Copyright (c) 1980, 1991, 1993 2.\" Regents of the University of California. 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 3. All advertising materials mentioning features or use of this software 14.\" must display the following acknowledgement: 15.\" This product includes software developed by the University of 16.\" California, Berkeley and its contributors. 17.\" 4. Neither the name of the University nor the names of its contributors 18.\" may be used to endorse or promote products derived from this software 19.\" without specific prior written permission. 20.\" 21.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31.\" SUCH DAMAGE. 32.\" 33.\" @(#)dump.8 8.3 (Berkeley) 5/1/95 34.\" $Id: dump.8,v 1.14 1997/03/15 06:23:57 peter Exp $ 35.\" 36.Dd May 1, 1995 37.Dt DUMP 8 38.Os BSD 4 39.Sh NAME 40.Nm dump 41.Nd filesystem backup 42.Sh SYNOPSIS 43.Nm dump 44.Op Fl 0123456789acknu 45.Op Fl B Ar records 46.Op Fl b Ar blocksize 47.Op Fl d Ar density 48.Op Fl f Ar file 49.Op Fl h Ar level 50.Op Fl s Ar feet 51.Op Fl T Ar date 52.Ar filesystem 53.Nm dump 54.Op Fl W Li \&| Fl w 55.Pp 56.in -\\n(iSu 57(The 58.Bx 4.3 59option syntax is implemented for backward compatibility, but 60is not documented here.) 61.Sh DESCRIPTION 62.Nm Dump 63examines files 64on a filesystem 65and determines which files 66need to be backed up. These files 67are copied to the given disk, tape or other 68storage medium for safe keeping (see the 69.Fl f 70option below for doing remote backups). 71A dump that is larger than the output medium is broken into 72multiple volumes. 73On most media the size is determined by writing until an 74end-of-media indication is returned. This can be enforced 75by using the 76.Fl a 77option. 78.Pp 79On media that cannot reliably return an end-of-media indication 80(such as some cartridge tape drives) 81each volume is of a fixed size; 82the actual size is determined by the tape size and density and/or 83block count options below. 84By default, the same output file name is used for each volume 85after prompting the operator to change media. 86.Pp 87The following options are supported by 88.Nm dump : 89.Bl -tag -width Ds 90.It Fl 0\-9 91Dump levels. 92A level 0, full backup, 93guarantees the entire file system is copied 94(but see also the 95.Fl h 96option below). 97A level number above 0, 98incremental backup, 99tells dump to 100copy all files new or modified since the 101last dump of the same or lower level. 102The default level is 9. 103.It Fl B Ar records 104The number of dump records per volume. 105This option overrides the calculation of tape size 106based on length and density. 107.It Fl a 108.Dq auto-size . 109Bypass all tape length considerations, and enforce writing 110until an end-of-media indication is returned. This fits best 111for most modern tape drives. Use of this option is particularly 112recommended when appending to an existing tape, or using a tape 113drive with hardware compression (where you can never be sure about 114the compression ratio). 115.It Fl b Ar blocksize 116The number of kilobytes per dump record. 117.It Fl c 118Change the defaults for use with a cartridge tape drive, with a density 119of 8000 bpi, and a length of 1700 feet. 120.It Fl h Ar level 121Honor the user 122.Dq nodump 123flag 124.Dp Dv UF_NODUMP 125only for dumps at or above the given 126.Ar level . 127The default honor level is 1, 128so that incremental backups omit such files 129but full backups retain them. 130.It Fl d Ar density 131Set tape density to 132.Ar density . 133The default is 1600BPI. 134.It Fl f Ar file 135Write the backup to 136.Ar file ; 137.Ar file 138may be a special device file 139like 140.Pa /dev/rst0 141(a tape drive), 142.Pa /dev/rfd1 143(a floppy disk drive), 144an ordinary file, 145or 146.Ql Fl 147(the standard output). 148Multiple file names may be given as a single argument separated by commas. 149Each file will be used for one dump volume in the order listed; 150if the dump requires more volumes than the number of names given, 151the last file name will used for all remaining volumes after prompting 152for media changes. 153If the name of the file is of the form 154.Dq host:file , 155or 156.Dq user@host:file , 157.Nm dump 158writes to the named file on the remote host using 159.Xr rmt 8 . 160The default path name of the remote 161.Xr rmt 8 162program is 163.\" rmt path, is the path on the remote host 164.Pa /etc/rmt ; 165this can be overridden by the environment variable 166.Ev RMT . 167.It Fl k 168Use Kerberos authentication to talk to remote tape servers. (Only 169available if this option was enabled when 170.Nm dump 171was compiled.) 172.It Fl n 173Whenever 174.Nm dump 175requires operator attention, 176notify all operators in the group 177.Dq operator 178by means similar to a 179.Xr wall 1 . 180.It Fl s Ar feet 181Attempt to calculate the amount of tape needed 182at a particular density. 183If this amount is exceeded, 184.Nm dump 185prompts for a new tape. 186It is recommended to be a bit conservative on this option. 187The default tape length is 2300 feet. 188.ne 1i 189.It Fl T Ar date 190Use the specified date as the starting time for the dump 191instead of the time determined from looking in 192.Pa /etc/dumpdates . 193The format of date is the same as that of 194.Xr ctime 3 . 195This option is useful for automated dump scripts that wish to 196dump over a specific period of time. 197The 198.Fl T 199option is mutually exclusive from the 200.Fl u 201option. 202.It Fl u 203Update the file 204.Pa /etc/dumpdates 205after a successful dump. 206The format of 207.Pa /etc/dumpdates 208is readable by people, consisting of one 209free format record per line: 210filesystem name, 211increment level 212and 213.Xr ctime 3 214format dump date. 215There may be only one entry per filesystem at each level. 216The file 217.Pa /etc/dumpdates 218may be edited to change any of the fields, 219if necessary. 220.It Fl W 221.Nm Dump 222tells the operator what file systems need to be dumped. 223This information is gleaned from the files 224.Pa /etc/dumpdates 225and 226.Pa /etc/fstab . 227The 228.Fl W 229option causes 230.Nm dump 231to print out, for each file system in 232.Pa /etc/dumpdates 233the most recent dump date and level, 234and highlights those file systems that should be dumped. 235If the 236.Fl W 237option is set, all other options are ignored, and 238.Nm dump 239exits immediately. 240.It Fl w 241Is like W, but prints only those filesystems which need to be dumped. 242.El 243.Pp 244.Nm Dump 245requires operator intervention on these conditions: 246end of tape, 247end of dump, 248tape write error, 249tape open error or 250disk read error (if there are more than a threshold of 32). 251In addition to alerting all operators implied by the 252.Fl n 253key, 254.Nm dump 255interacts with the operator on 256.Em dump's 257control terminal at times when 258.Nm dump 259can no longer proceed, 260or if something is grossly wrong. 261All questions 262.Nm dump 263poses 264.Em must 265be answered by typing 266.Dq yes 267or 268.Dq no , 269appropriately. 270.Pp 271Since making a dump involves a lot of time and effort for full dumps, 272.Nm dump 273checkpoints itself at the start of each tape volume. 274If writing that volume fails for some reason, 275.Nm dump 276will, 277with operator permission, 278restart itself from the checkpoint 279after the old tape has been rewound and removed, 280and a new tape has been mounted. 281.Pp 282.Nm Dump 283tells the operator what is going on at periodic intervals, 284including usually low estimates of the number of blocks to write, 285the number of tapes it will take, the time to completion, and 286the time to the tape change. 287The output is verbose, 288so that others know that the terminal 289controlling 290.Nm dump 291is busy, 292and will be for some time. 293.Pp 294In the event of a catastrophic disk event, the time required 295to restore all the necessary backup tapes or files to disk 296can be kept to a minimum by staggering the incremental dumps. 297An efficient method of staggering incremental dumps 298to minimize the number of tapes follows: 299.Bl -bullet -offset indent 300.It 301Always start with a level 0 backup, for example: 302.Bd -literal -offset indent 303/sbin/dump -0u -f /dev/nrst0 /usr/src 304.Ed 305.Pp 306This should be done at set intervals, say once a month or once every two months, 307and on a set of fresh tapes that is saved forever. 308.It 309After a level 0, dumps of active file 310systems are taken on a daily basis, 311using a modified Tower of Hanoi algorithm, 312with this sequence of dump levels: 313.Bd -literal -offset indent 3143 2 5 4 7 6 9 8 9 9 ... 315.Ed 316.Pp 317For the daily dumps, it should be possible to use a fixed number of tapes 318for each day, used on a weekly basis. 319Each week, a level 1 dump is taken, and 320the daily Hanoi sequence repeats beginning with 3. 321For weekly dumps, another fixed set of tapes per dumped file system is 322used, also on a cyclical basis. 323.El 324.Pp 325After several months or so, the daily and weekly tapes should get 326rotated out of the dump cycle and fresh tapes brought in. 327.Sh ENVIRONMENT 328The environment variable 329.Ev RMT 330will be used to determine the pathname of the remote 331.Xr rmt 8 332program. 333.Sh FILES 334.Bl -tag -width /etc/dumpdates -compact 335.It Pa /dev/rst0 336default tape unit to dump to 337.It Pa /etc/dumpdates 338dump date records 339.It Pa /etc/fstab 340dump table: file systems and frequency 341.It Pa /etc/group 342to find group 343.Em operator 344.El 345.Sh SEE ALSO 346.Xr dump 5 , 347.Xr fstab 5 , 348.Xr ft 8 , 349.Xr restore 8 , 350.Xr rmt 8 351.Sh DIAGNOSTICS 352Many, and verbose. 353.Pp 354Dump exits with zero status on success. 355Startup errors are indicated with an exit code of 1; 356abnormal termination is indicated with an exit code of 3. 357.Sh BUGS 358Fewer than 32 read errors on the filesystem are ignored. 359.Pp 360Each reel requires a new process, so parent processes for 361reels already written just hang around until the entire tape 362is written. 363.Pp 364Currently, 365.Xr physio 9 366slices all requests into chunks of 64 KB. Therefore, it is 367impossible to use a larger tape blocksize, so 368.Nm dump 369will prevent this from happening. 370.Pp 371.Nm Dump 372with the 373.Fl W 374or 375.Fl w 376options does not report filesystems that have never been recorded 377in 378.Pa /etc/dumpdates , 379even if listed in 380.Pa /etc/fstab . 381.Pp 382It would be nice if 383.Nm dump 384knew about the dump sequence, 385kept track of the tapes scribbled on, 386told the operator which tape to mount when, 387and provided more assistance 388for the operator running 389.Xr restore . 390.Pp 391.Nm dump 392cannot do remote backups without being run as root, due to its 393security history. This will be fixed in a later version of FreeBSD. 394Presently, it work if you set it setuid (like it used to be), but this 395might constitute a security risk. 396.Sh HISTORY 397A 398.Nm dump 399command appeared in 400.At v6 . 401