System Administration Commands ufsdump(1M)
NAME
ufsdump - incremental file system dump
SYNOPSIS
/usr/sbin/ufsdump [options] [arguments] files_to_dump
DESCRIPTION
ufsdump backs up all files specified by files_to_dump (usu-
ally either a whole file system or files within a file sytem changed after a certain date) to magnetic tape, diskette, or disk file.The ufsdump command can only be used on unmounted file sys-
tems, or those mounted read-only. Attempting to dump a
mounted, read-write file system might result in a system
disruption or the inability to restore files from the dump.Consider using the fssnap(1M) command to create a file sys-
tem snapshot if you need a point-in-time image of a file
system that is mounted. If a filesystem was mounted with the logging option, it isstrongly recommended that you run ufsdump as the root user.
Running the command as a non-root user might result in the
creation of an inconsistent dump.options is a single string of one-letter ufsdump options.
arguments may be multiple strings whose association with the options is determined by order. That is, the first argument goes with the first option that takes an argument; the second argument goes with the second option that takes an argument, and so on.files_to_dump is required and must be the last argument on
the command line. See OPERANDS for more information.With most devices ufsdump can automatically detect the end-
of-media. Consequently, the d, s, and t options are not
necessary for multi-volume dumps, unless ufsdump does not
understand the way the device detects the end-of-media, or
the files are to be restored on a system with an older ver-
sion of the restore command. OPTIONSSunOS 5.11 Last change: 17 Mar 2008 1
System Administration Commands ufsdump(1M)
The following options are supported:0-9
The "dump level." All files specified by files_to_dump
that have been modified since the last ufsdump at a
lower dump level are copied to the dump_file destination
(normally a magnetic tape device). For instance, if a "level 2" dump was done on Monday, followed by a "level 4" dump on Tuesday, a subsequent "level 3" dump on Wednesday would contain all files modified or added since the "level 2" (Monday) backup. A "level 0" dumpcopies the entire file system to the dump_file.
a archive_file
Archive file. Archive a dump table-of-contents in the
specified archive_file to be used by ufsrestore(1M) to
determine whether a file is in the dump file that is being restored. b factor Blocking factor. Specify the blocking factor for tape writes. The default is 20 blocks per write for tapes ofdensity less than 6250BPI (bytes-per-inch). The default
blocking factor for tapes of density 6250BPI and greater is 64. The default blocking factor for cartridge tapes (c option) is 126. The highest blocking factor available with most tape drives is 126. Note: the blocking factoris specified in terms of 512-byte blocks, for compati-
bility with tar(1). c Cartridge. Set the defaults for cartridge instead of thestandard half-inch reel. This sets the density to
1000BPI and the blocking factor to 126. Since ufsdump
can automatically detect the end-of-media, only the
blocking parameter normally has an effect. When car-
tridge tapes are used, and this option is not specified,ufsdump will slightly miscompute the size of the tape.
If the b, d, s or t options are specified with this option, their values will override the defaults set by this option. d bpiSunOS 5.11 Last change: 17 Mar 2008 2
System Administration Commands ufsdump(1M)
Tape density. Not normally required, as ufsdump can
detect end-of-media. This parameter can be used to keep
a running tab on the amount of tape used per reel. The default density is 6250BPI except when the c option is used for cartridge tape, in which case it is assumed to be 1000BPI per track. Typical values for tape devices are: 1/2 inch tape 6250 BPI 1/4 inch cartridge 1000 BPI The tape densities and other options are documented in the st(7D) man page. D Diskette. Dump to diskette.f dump_file
Dump file. Use dump_file as the file to dump to, instead
of /dev/rmt/0. If dump_file is specified as -, dump to
standard output. If the name of the file is of the form machine:device, the dump is done from the specified machine over thenetwork using rmt(1M). Since ufsdump is normally run by
root, the name of the local machine must appear in the /.rhosts file of the remote machine. If the file isspecified as user@machine:device, ufsdump will attempt
to execute as the specified user on the remote machine. The specified user must have a .rhosts file on the remote machine that allows the user invoking the command from the local machine to access the remote machine. lAutoload. When the end-of-tape is reached before the
dump is complete, take the drive offline and wait up to two minutes for the tape drive to be ready again. This gives autoloading (stackloader) tape drives a chance to load a new tape. If the drive is ready within two minutes, continue. If it is not, prompt for another tape and wait.SunOS 5.11 Last change: 17 Mar 2008 3
System Administration Commands ufsdump(1M)
L string Sets the tape label to string, instead of the default none. string may be no more than sixteen characters long. If it is longer, it is truncated and a warning printed; the dump will still be done. The tape label isspecific to the ufsdump tape format, and bears no resem-
blance to IBM or ANSI-standard tape labels.
nNotify all operators in the sys group that ufsdump
requires attention by sending messages to their termi-
nals, in a manner similar to that used by the wall(1M) command. Otherwise, such messages are sent only to theterminals (such as the console) on which the user run-
ning ufsdump is logged in.
N device_name
Use device_name when recording information in
/etc/dumpdates (see the u option) and when comparing against information in /etc/dumpdates for incrementaldumps. The device_name provided can contain no white
space as defined in scanf(3C) and is case-sensitive.
oOffline. Take the drive offline when the dump is com-
plete or the end-of-media is reached and rewind the
tape, or eject the diskette. In the case of some auto-
loading 8mm drives, the tape is removed from the drive automatically. This prevents another process whichrushes in to use the drive, from inadvertently overwrit-
ing the media. s sizeSpecify the size of the volume being dumped to. Not nor-
mally required, as ufsdump can detect end-of-media. When
the specified size is reached, ufsdump waits for you to
change the volume. ufsdump interprets the specified size
as the length in feet for tapes and cartridges, and asthe number of 1024-byte blocks for diskettes. The values
should be a little smaller than the actual physical sizeof the media (for example, 425 for a 450-foot car-
tridge). Typical values for tape devices depend on the c option, for cartridge devices, and the D option forSunOS 5.11 Last change: 17 Mar 2008 4
System Administration Commands ufsdump(1M)
diskettes: 1/2 inch tape 2300 feet60-Mbyte 1/4 inch cartridge
425 feet150-Mbyte 1/4 inch cartridge
700 feet diskette1422 blocks (Corresponds to a 1.44-Mbyte diskette,
with one cylinder reserved for bad block informa-
tion.) S Size estimate. Determine the amount of space that is needed to perform the dump without actually doing it, and display the estimated number of bytes it will take. This is useful with incremental dumps to determine how many volumes of media will be needed. t tracks Specify the number of tracks for a cartridge tape. Notnormally required, as ufsdump can detect end-of-media.
The default is 9 tracks. The t option is not compatiblewith the D option. Values for Sun-supported tape devices
are:60-Mbyte 1/4 inch cartridge
9 tracks150-Mbyte 1/4 inch cartridge
18 tracksSunOS 5.11 Last change: 17 Mar 2008 5
System Administration Commands ufsdump(1M)
T time_wait[hms]
Sets the amount of time to wait for an autoload command to complete. This option is ignored unless the l option has also been specified. The default time period to wait is two minutes. Specify time units with a trailing h ( for hours), m (for minutes), or s (for seconds). The default unit is minutes. u Update the dump record. Add an entry to the file /etc/dumpdates, for each file system successfully dumpedthat includes the file system name (or device_name as
specified with the N option), date, and dump level. v Verify. After each tape or diskette is written, verifythe contents of the media against the source file sys-
tem. If any discrepancies occur, prompt for new media,then repeat the dump/verification process. The file sys-
tem must be unmounted. This option cannot be used to verify a dump to standard output. w Warning. List the file systems that have not been backed up within a day. This information is gleaned from the files /etc/dumpdates and /etc/vfstab. When the w option is used, all other options are ignored. After reporting,ufsdump exits immediately.
W Warning with highlight. Similar to the w option, except that the W option includes all file systems that appear in /etc/dumpdates, along with information about their most recent dump dates and levels. File systems that have not been backed up within a day are highlighted. OPERANDS The following operand is supported:files_to_dump
Specifies the files to dump. Usually it identifies aSunOS 5.11 Last change: 17 Mar 2008 6
System Administration Commands ufsdump(1M)
whole file system by its raw device name (for example, /dev/rdsk/c0t3d0s6). Incremental dumps (levels 1 to 9) of files changed after a certain date only apply to awhole file system. Alternatively, files_to_dump can
identify individual files or directories. All named directories that may be examined by the user runningufsdump, as well as any explicitly-named files, are
dumped. This dump is equivalent to a level 0 dump of the indicated portions of the filesystem, except that/etc/dumpdates is not updated even if the -u option has
been specified. In all cases, the files must be con-
tained in the same file system, and the file system mustbe local to the system where ufsdump is being run.
files_to_dump is required and must be the last argument
on the command line. If no options are given, the default is 9uf /dev/rmt/0files_to_dump.
USAGE
See largefile(5) for the description of the behavior of ufs-
dump when encountering files greater than or equal to 2 Gbyte ( 2^31 bytes).EXAMPLES
Example 1 Using ufsdump
The following command makes a full dump of a root file sys-
tem on c0t3d0, on a 150-MByte cartridge tape unit 0:
example# ufsdump 0cfu /dev/rmt/0 /dev/rdsk/c0t3d0s0
The following command makes and verifies an incremental dump at level 5 of the usr partition of c0t3d0, on a 1/2 inch reel tape unit 1,:example# ufsdump 5fuv /dev/rmt/1 /dev/rdsk/c0t3d0s6
EXIT STATUSWhile running, ufsdump emits many verbose messages. ufsdump
returns the following exit values:SunOS 5.11 Last change: 17 Mar 2008 7
System Administration Commands ufsdump(1M)
0 Normal exit. 1 Startup errors encountered. 3Abort - no checkpoint attempted.
FILES /dev/rmt/0 default unit to dump to /etc/dumpdates dump date record /etc/group to find group sys /etc/hosts to gain access to remote system with drive /etc/vfstab list of file systemsATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:SunOS 5.11 Last change: 17 Mar 2008 8
System Administration Commands ufsdump(1M)
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | SUNWcs ||_____________________________|_____________________________|
SEE ALSO
cpio(1), tar(1), dd(1M), devnm(1M), fssnap(1M), prtvtoc(1M), rmt(1M), shutdown(1M), ufsrestore(1M), volcopy(1M),wall(1M), scanf(3C), ufsdump(4), attributes(5), large-
file(5), st(7D) NOTES Read Errors Fewer than 32 read errors on the file system are ignored. Process Per Reel Because each reel requires a new process, parent processes for reels that are already written hang around until the entire tape is written. Operator Interventionufsdump requires operator intervention on these conditions:
end of volume, end of dump, volume write error, volume open error or disk read error (if there are more than a threshold of 32). In addition to alerting all operators implied by then option, ufsdump interacts with the operator on ufsdump's
control terminal at times when ufsdump can no longer
proceed, or if something is grossly wrong. All questionsufsdump poses must be answered by typing yes or no, as
appropriate. Since backing up a disk can involve a lot of time andeffort, ufsdump checkpoints at the start of each volume. If
writing that volume fails for some reason, ufsdump will,
with operator permission, restart itself from the checkpoint after a defective volume has been replaced. Suggested Dump Schedule It is vital to perform full, "level 0", dumps at regular intervals. When performing a full dump, bring the machinedown to single-user mode using shutdown(1M). While preparing
for a full dump, it is a good idea to clean the tape drive and heads. Incremental dumps should be performed with thesystem running in single-user mode.
Incremental dumps allow for convenient backup and recovery of active files on a more frequent basis, with a minimum of media and time. However, there are some tradeoffs. First,SunOS 5.11 Last change: 17 Mar 2008 9
System Administration Commands ufsdump(1M)
the interval between backups should be kept to a minimum (once a day at least). To guard against data loss as a result of a media failure (a rare, but possible occurrence), capture active files on (at least) two sets of dump volumes. Another consideration is the desire to keep unnecessary duplication of files to a minimum to save both operator time and media storage. A third consideration is the ease withwhich a particular backed-up version of a file can be
located and restored. The following four-week schedule
offers a reasonable tradeoff between these goals. Sun Mon Tue Wed Thu Fri Week 1: Full 5 5 5 5 3 Week 2: 5 5 5 5 3 Week 3: 5 5 5 5 3 Week 4: 5 5 5 5 3 Although the Tuesday through Friday incrementals contain "extra copies" of files from Monday, this scheme assures that any file modified during the week can be recovered from the previous day's incremental dump.Process Priority of ufsdump
ufsdump uses multiple processes to allow it to read from the
disk and write to the media concurrently. Due to the way it synchronizes between these processes, any attempt to rundump with a nice (process priority) of `-5' or better will
likely make ufsdump run slower instead of faster.
Overlapping Partitions Most disks contain one or more overlapping slices because slice 2 covers the entire disk. The other slices are of various sizes and usually do not overlap. For example, a common configuration places root on slice 0, swap on slice 1, /opt on slice 5 and /usr on slice 6.It should be emphasized that ufsdump dumps one ufs file sys-
tem at a time. Given the above scenario where slice 0 andslice 2 have the same starting offset, executing ufsdump on
slice 2 with the intent of dumping the entire disk would instead dump only the root file system on slice 0. To dump the entire disk, the user must dump the file systems on each slice separately.BUGS
The /etc/vfstab file does not allow the desired frequency of backup for file systems to be specified (as /etc/fstab did). Consequently, the w and W options assume file systems shouldSunOS 5.11 Last change: 17 Mar 2008 10
System Administration Commands ufsdump(1M)
be backed up daily, which limits the usefulness of these options.SunOS 5.11 Last change: 17 Mar 2008 11