1ufsdump(1M) System Administration Commands ufsdump(1M)
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6 ufsdump - incremental file system dump
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9 /usr/sbin/ufsdump [options] [arguments] files_to_dump
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13 ufsdump backs up all files specified by files_to_dump (usually either a
14 whole file system or files within a file sytem changed after a certain
15 date) to magnetic tape, diskette, or disk file.
16 The ufsdump command can only be used on unmounted file systems, or
19 those mounted read-only. Attempting to dump a mounted, read-write file
20 system might result in a system disruption or the inability to restore
21 files from the dump. Consider using the fssnap(1M) command to create a
22 file system snapshot if you need a point-in-time image of a file system
23 that is mounted.
24 If a filesystem was mounted with the logging option, it is strongly
27 recommended that you run ufsdump as the root user. Running the command
28 as a non-root user might result in the creation of an inconsistent
29 dump.
30 options is a single string of one-letter ufsdump options.
33 arguments may be multiple strings whose association with the options is
36 determined by order. That is, the first argument goes with the first
37 option that takes an argument; the second argument goes with the second
38 option that takes an argument, and so on.
39 files_to_dump is required and must be the last argument on the command
42 line. See OPERANDS for more information.
43 With most devices ufsdump can automatically detect the end-of-media.
46 Consequently, the d, s, and t options are not necessary for multi-vol‐
47 ume dumps, unless ufsdump does not understand the way the device
48 detects the end-of-media, or the files are to be restored on a system
49 with an older version of the restore command.
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52 The following options are supported:
53 0−9
55 The "dump level." All files specified by files_to_dump that have
57 been modified since the last ufsdump at a lower dump level are
58 copied to the dump_file destination (normally a magnetic tape
59 device). For instance, if a "level 2" dump was done on Monday, fol‐
60 lowed by a "level 4" dump on Tuesday, a subsequent "level 3" dump
61 on Wednesday would contain all files modified or added since the
62 "level 2" (Monday) backup. A "level 0" dump copies the entire file
63 system to the dump_file.
64 a archive_file
67 Archive file. Archive a dump table-of-contents in the specified ar‐
69 chive_file to be used by ufsrestore(1M) to determine whether a file
70 is in the dump file that is being restored.
71 b factor
74 Blocking factor. Specify the blocking factor for tape writes. The
76 default is 20 blocks per write for tapes of density less than
77 6250BPI (bytes-per-inch). The default blocking factor for tapes of
78 density 6250BPI and greater is 64. The default blocking factor for
79 cartridge tapes (c option) is 126. The highest blocking factor
80 available with most tape drives is 126. Note: the blocking factor
81 is specified in terms of 512-byte blocks, for compatibility with
82 tar(1).
83 c
86 Cartridge. Set the defaults for cartridge instead of the standard
88 half-inch reel. This sets the density to 1000BPI and the blocking
89 factor to 126. Since ufsdump can automatically detect the end-of-
90 media, only the blocking parameter normally has an effect. When
91 cartridge tapes are used, and this option is not specified, ufsdump
92 will slightly miscompute the size of the tape. If the b, d, s or t
93 options are specified with this option, their values will override
94 the defaults set by this option.
95 d bpi
98 Tape density. Not normally required, as ufsdump can detect end-of-
100 media. This parameter can be used to keep a running tab on the
101 amount of tape used per reel. The default density is 6250BPI except
102 when the c option is used for cartridge tape, in which case it is
103 assumed to be 1000BPI per track. Typical values for tape devices
104 are:
105 1/2 inch tape
107 6250 BPI
109 1/4 inch cartridge
112 1000 BPI The tape densities and other options are documented in
114 the st(7D) man page.
115 D
119 Diskette. Dump to diskette.
121 f dump_file
124 Dump file. Use dump_file as the file to dump to, instead of
126 /dev/rmt/0. If dump_file is specified as −, dump to standard out‐
127 put.
128 If the name of the file is of the form machine:device, the dump is
130 done from the specified machine over the network using rmt(1M).
131 Since ufsdump is normally run by root, the name of the local
132 machine must appear in the /.rhosts file of the remote machine. If
133 the file is specified as user@machine:device, ufsdump will attempt
134 to execute as the specified user on the remote machine. The speci‐
135 fied user must have a .rhosts file on the remote machine that
136 allows the user invoking the command from the local machine to
137 access the remote machine.
138 l
141 Autoload. When the end-of-tape is reached before the dump is com‐
143 plete, take the drive offline and wait up to two minutes for the
144 tape drive to be ready again. This gives autoloading (stackloader)
145 tape drives a chance to load a new tape. If the drive is ready
146 within two minutes, continue. If it is not, prompt for another tape
147 and wait.
148 L string
151 Sets the tape label to string, instead of the default none. string
153 may be no more than sixteen characters long. If it is longer, it is
154 truncated and a warning printed; the dump will still be done. The
155 tape label is specific to the ufsdump tape format, and bears no
156 resemblance to IBM or ANSI-standard tape labels.
157 n
160 Notify all operators in the sys group that ufsdump requires atten‐
162 tion by sending messages to their terminals, in a manner similar to
163 that used by the wall(1M) command. Otherwise, such messages are
164 sent only to the terminals (such as the console) on which the user
165 running ufsdump is logged in.
166 N device_name
169 Use device_name when recording information in /etc/dumpdates (see
171 the u option) and when comparing against information in /etc/dump‐
172 dates for incremental dumps. The device_name provided can contain
173 no white space as defined in scanf(3C) and is case-sensitive.
174 o
177 Offline. Take the drive offline when the dump is complete or the
179 end-of-media is reached and rewind the tape, or eject the diskette.
180 In the case of some autoloading 8mm drives, the tape is removed
181 from the drive automatically. This prevents another process which
182 rushes in to use the drive, from inadvertently overwriting the
183 media.
184 s size
187 Specify the size of the volume being dumped to. Not normally
189 required, as ufsdump can detect end-of-media. When the specified
190 size is reached, ufsdump waits for you to change the volume. ufs‐
191 dump interprets the specified size as the length in feet for tapes
192 and cartridges, and as the number of 1024-byte blocks for
193 diskettes. The values should be a little smaller than the actual
194 physical size of the media (for example, 425 for a 450-foot car‐
195 tridge). Typical values for tape devices depend on the c option,
196 for cartridge devices, and the D option for diskettes:
197 1/2 inch tape
199 2300 feet
201 60-Mbyte 1/4 inch cartridge
204 425 feet
206 150-Mbyte 1/4 inch cartridge
209 700 feet
211 diskette
214 1422 blocks (Corresponds to a 1.44-Mbyte diskette, with one
216 cylinder reserved for bad block information.)
217 S
221 Size estimate. Determine the amount of space that is needed to per‐
223 form the dump without actually doing it, and display the estimated
224 number of bytes it will take. This is useful with incremental dumps
225 to determine how many volumes of media will be needed.
226 t tracks
229 Specify the number of tracks for a cartridge tape. Not normally
231 required, as ufsdump can detect end-of-media. The default is 9
232 tracks. The t option is not compatible with the D option. Values
233 for Sun-supported tape devices are:
234 60-Mbyte 1/4 inch cartridge
236 9 tracks
238 150-Mbyte 1/4 inch cartridge
241 18 tracks
243 T time_wait[hms]
247 Sets the amount of time to wait for an autoload command to com‐
249 plete. This option is ignored unless the l option has also been
250 specified. The default time period to wait is two minutes. Specify
251 time units with a trailing h ( for hours), m (for minutes), or s
252 (for seconds). The default unit is minutes.
253 u
256 Update the dump record. Add an entry to the file /etc/dumpdates,
258 for each file system successfully dumped that includes the file
259 system name (or device_name as specified with the N option), date,
260 and dump level.
261 v
264 Verify. After each tape or diskette is written, verify the contents
266 of the media against the source file system. If any discrepancies
267 occur, prompt for new media, then repeat the dump/verification
268 process. The file system must be unmounted. This option cannot be
269 used to verify a dump to standard output.
270 w
273 Warning. List the file systems that have not been backed up within
275 a day. This information is gleaned from the files /etc/dumpdates
276 and /etc/vfstab. When the w option is used, all other options are
277 ignored. After reporting, ufsdump exits immediately.
278 W
281 Warning with highlight. Similar to the w option, except that the W
283 option includes all file systems that appear in /etc/dumpdates,
284 along with information about their most recent dump dates and lev‐
285 els. File systems that have not been backed up within a day are
286 highlighted.
287
290 The following operand is supported:
291 files_to_dump
293 Specifies the files to dump. Usually it identifies a whole file
295 system by its raw device name (for example, /dev/rdsk/c0t3d0s6).
296 Incremental dumps (levels 1 to 9) of files changed after a certain
297 date only apply to a whole file system. Alternatively,
298 files_to_dump can identify individual files or directories. All
299 named directories that may be examined by the user running ufsdump,
300 as well as any explicitly-named files, are dumped. This dump is
301 equivalent to a level 0 dump of the indicated portions of the
302 filesystem, except that /etc/dumpdates is not updated even if the
303 -u option has been specified. In all cases, the files must be con‐
304 tained in the same file system, and the file system must be local
305 to the system where ufsdump is being run.
306 files_to_dump is required and must be the last argument on the com‐
308 mand line.
309 If no options are given, the default is 9uf /dev/rmt/0 files_to_dump.
313
315 See largefile(5) for the description of the behavior of ufsdump when
316 encountering files greater than or equal to 2 Gbyte ( 2^31 bytes).
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319 Example 1 Using ufsdump
320 The following command makes a full dump of a root file system on
323 c0t3d0, on a 150-MByte cartridge tape unit 0:
324 example# ufsdump 0cfu /dev/rmt/0 /dev/rdsk/c0t3d0s0
327 The following command makes and verifies an incremental dump at level 5
332 of the usr partition of c0t3d0, on a 1/2 inch reel tape unit 1,:
333 example# ufsdump 5fuv /dev/rmt/1 /dev/rdsk/c0t3d0s6
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340 While running, ufsdump emits many verbose messages. ufsdump returns the
341 following exit values:
342 0
344 Normal exit.
346 1
349 Startup errors encountered.
351 3
354 Abort − no checkpoint attempted.
356
359 /dev/rmt/0
360 default unit to dump to
362 /etc/dumpdates
365 dump date record
367 /etc/group
370 to find group sys
372 /etc/hosts
375 to gain access to remote system with drive
377 /etc/vfstab
380 list of file systems
382
385 See attributes(5) for descriptions of the following attributes:
386 ┌─────────────────────────────┬─────────────────────────────┐
391 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
392 ├─────────────────────────────┼─────────────────────────────┤
393 │Availability │SUNWcsu │
394 └─────────────────────────────┴─────────────────────────────┘
395
397 cpio(1), tar(1), dd(1M), devnm(1M), fssnap(1M), prtvtoc(1M), rmt(1M),
398 shutdown(1M), ufsrestore(1M), volcopy(1M), wall(1M), scanf(3C), ufs‐
399 dump(4), attributes(5), largefile(5), st(7D)
400
402 Read Errors
403 Fewer than 32 read errors on the file system are ignored.
404 Process Per Reel
406 Because each reel requires a new process, parent processes for reels
407 that are already written hang around until the entire tape is written.
408 Operator Intervention
410 ufsdump requires operator intervention on these conditions: end of vol‐
411 ume, end of dump, volume write error, volume open error or disk read
412 error (if there are more than a threshold of 32). In addition to alert‐
413 ing all operators implied by the n option, ufsdump interacts with the
414 operator on ufsdump's control terminal at times when ufsdump can no
415 longer proceed, or if something is grossly wrong. All questions ufsdump
416 poses must be answered by typing yes or no, as appropriate.
417 Since backing up a disk can involve a lot of time and effort, ufsdump
420 checkpoints at the start of each volume. If writing that volume fails
421 for some reason, ufsdump will, with operator permission, restart itself
422 from the checkpoint after a defective volume has been replaced.
423 Suggested Dump Schedule
425 It is vital to perform full, "level 0", dumps at regular intervals.
426 When performing a full dump, bring the machine down to single-user mode
427 using shutdown(1M). While preparing for a full dump, it is a good idea
428 to clean the tape drive and heads. Incremental dumps should be per‐
429 formed with the system running in single-user mode.
430 Incremental dumps allow for convenient backup and recovery of active
433 files on a more frequent basis, with a minimum of media and time. How‐
434 ever, there are some tradeoffs. First, the interval between backups
435 should be kept to a minimum (once a day at least). To guard against
436 data loss as a result of a media failure (a rare, but possible occur‐
437 rence), capture active files on (at least) two sets of dump volumes.
438 Another consideration is the desire to keep unnecessary duplication of
439 files to a minimum to save both operator time and media storage. A
440 third consideration is the ease with which a particular backed-up ver‐
441 sion of a file can be located and restored. The following four-week
442 schedule offers a reasonable tradeoff between these goals.
443 Sun Mon Tue Wed Thu Fri
445 Week 1: Full 5 5 5 5 3
446 Week 2: 5 5 5 5 3
447 Week 3: 5 5 5 5 3
448 Week 4: 5 5 5 5 3
449 Although the Tuesday through Friday incrementals contain "extra copies"
454 of files from Monday, this scheme assures that any file modified during
455 the week can be recovered from the previous day's incremental dump.
456 Process Priority of ufsdump
458 ufsdump uses multiple processes to allow it to read from the disk and
459 write to the media concurrently. Due to the way it synchronizes between
460 these processes, any attempt to run dump with a nice (process priority)
461 of `−5' or better will likely make ufsdump run slower instead of
462 faster.
463 Overlapping Partitions
465 Most disks contain one or more overlapping slices because slice 2 cov‐
466 ers the entire disk. The other slices are of various sizes and usually
467 do not overlap. For example, a common configuration places root on
468 slice 0, swap on slice 1, /opt on slice 5 and /usr on slice 6.
469 It should be emphasized that ufsdump dumps one ufs file system at a
472 time. Given the above scenario where slice 0 and slice 2 have the same
473 starting offset, executing ufsdump on slice 2 with the intent of dump‐
474 ing the entire disk would instead dump only the root file system on
475 slice 0. To dump the entire disk, the user must dump the file systems
476 on each slice separately.
477
479 The /etc/vfstab file does not allow the desired frequency of backup for
480 file systems to be specified (as /etc/fstab did). Consequently, the w
481 and W options assume file systems should be backed up daily, which lim‐
482 its the usefulness of these options.
483SunOS 5.11 17 Mar 2008 ufsdump(1M)