dump, rdump - Performs incremental file system dumps
/usr/sbin/dump [key[argument...] file system]
/usr/sbin/rdump -fdump_file [otherkey[argument...]file
system]
rdump
Specifies the dump level. All files modified since the
last time-stamp whose names are currently stored in the
/etc/dumpdates file for a named file system at levels less
than the one specified are dumped to tape. When no timestamp
entry is defined for a dump level, the Epoch is
assumed; thus, the value -0 for this key causes the entire
file system to be dumped to the storage medium. Specifies
the number of blocks in 1024 bytes to write to the storage
medium. The default write block value is 10 blocks (or 10
kilobytes). In many instances, increasing the number of
blocks per write will increase your dump performance. For
optimal results on AlphaServers, use a value that is
greater than or equal to 32, is a multiple of 4, and is
less than 65. The dump medium is a not a 9-track cartridge
tape. Specifies the write density of the storage
medium. The density operand is expressed in bits per inch
(bpi). This information is used in calculating the amount
of medium used per each volume of the storage medium. For
the dump command, the density will be automatically provided
by supported devices. Otherwise, the default write
density for the dump and rdump commands is 1600 bpi.
Writes the dump to the dump_file storage device instead of
the default tape drive. When the name of dump_file is -
(dash), the dump process writes to standard output. When
the name of the dump_file is /dev/ntape/tape?*, the dump
process will enable the -N option. When the rdump command
is invoked, the dump_file operand must specify both the
remote machine and the storage device in the format
[user@]machine:device, where where user is an optional
user identification (account) used to logon to the
machine. If you do not specify user rdump will use the
user identification from the current process. The machine
is the name or reference designation of the host machine,
and device is the name or reference designation of the
storage device. If you want to specify an IPv6 address for
machine, you must prefix the address with the \[ (backslash,
left bracket) characters and terminate the address
with the \] (backslash, right bracket) characters.
Because the bracket characters are shell metacharacters,
your must precede them with the backslash character.
Specifies the label of the dump to be displayed during
restoration. The default label is "No Label". The label
can be a maximum of 16 characters. Notifies, by means of
a command similar to wall(1), all operators in the group
named operator, which is specified in the /etc/group file
whenever dump or rdump requires operator attention (to
change a tape, for example). Specifies the size of a dump
tape. The size operand is expressed in feet. When the
amount of tape specified by size has been written, either
process waits for the current reel to be changed (see the
-n option). For the dump command, the tape size will be
automatically provided by supported devices. Otherwise,
the default tape size for the dump and rdump commands is
2300 feet. Writes the time of the beginning of the dump
as the time-stamp entry in the /etc/dumpdates file for the
file system record when the dump successfully completes.
Tells an operator what file systems must be dumped to the
storage device. This information is obtained from the
/etc/dumpdates and /etc/fstab files. The -w key tells
either process to print to the standard output a record
for each file system listed in the /etc/dumpdates file.
Specifies a block-mode device. For the dump command, the
estimated calculations will be based on the device's storage
capacity instead of density and size. Prints the
estimated size of the dump file in 1-kilobyte blocks and
the estimated number of volumes that make up the dump
file, only. The dump file will be opened and closed, but
nothing will be written to it. The information will be
output through standard error and will have a format like
the following: 23382 blocks, 0.04 volumes
If the dump file is on disk, the format will be:
23382 blocks
The operand placement will be preserved, but the
exact words "blocks," and "volumes" are not guaranteed.
Refer to the EXAMPLES section for further
information. Disables the rewinding of the tape
and placing the tape unit off line after completing
the dump session. By default, when the dump command
finishes backing up a file system it rewinds
the tape and takes it off line. For some tape subsystems,
this tape will be ejected from the unit.
The -N option is the default when the dump_file
operand is /dev/ntape/tape?. If you use the -N
option to dump to a regular file that does not have
the letters "rm" in its name, dump will inform you
of your error in using -N and terminate. Specifies
output file size in feet. When the -B option is
used, the full_tape_size operand specifies the output
file size in number of 1024-byte blocks. Specifies
a tape number, which is used in the dialog
with the operator as the number of the first tape.
Prevents any extended attributes from being
archived with associated files. Similar to -w, but
for any file system listed in the /etc/dumpdates
file, prints an output record and highlights this
record with the > (greater than) character, all
files that must be dumped. When -W is specified,
all other options are ignored and dump exits immediately.
The dump command copies to the default /dev/tape/tape0_d0,
or to the alternate storage device specified with the -f
option, all files and any associated extended attributes
(including ACLs, see the acl(4) and proplist(4) reference
pages) changed after a certain date in the specified local
file system.
The rdump command copies to the dump_file storage device
all files and any associated extended attributes (including
ACLs, see the acl(4) and proplist(4) reference pages)
changed after a certain date in the specified file system.
These commands cannot be used to archive AdvFS filesets.
See vdump(8) for the operations used to archive AdvFS
filesets.
The dump and rdump commands are used to dump local files
and any associated local attributes from a single file
system defined by the file system operand to a local or
remote storage device, respectively, where file system
contains the files you want to back up.
The dump and rdump commands perform similar functions with
respect to storage of files contained in the named file
system. However, the rdump command requires that the -f
option be used with any otherkey and the special dump_file
operand.
Both commands copy all files in file system whose dump
level is less than a specified value, and that have
changed after a specified date to the default storage
device or to an alternate storage device. The dump level
and date are specified in the local /etc/dumpdates file.
The key and argument operand specify one or more options
that may be used to write files to the storage medium.
Characters permitted by the key operand are similar to
options that consist of any of the characters
0123456789bcdfnsuwBNSTW only, which may be used in any
logical combination, but must be preceded with the -
(dash) character; the argument operand specifies other
options that tell these dump and rdump processes what to
do. These options are described in the OPTIONS section.
Not all keys permit argument options to be specified.
The /etc/dumpdates file consists of 3-column record lines
that specify the file system name, a dump level, and a
standard time-stamp. These processes enter a time-stamp
into the file system record after each file in the named
file system is successfully backed up. The 3-column
record in the /etc/dumpdates file contains the following
information:
Lists the file system device name. This is an integer
between 1 and 9 that defines a hierarchy for files in file
system. This hierarchy indicates which files should be
written to the storage medium when the dump or rdump command
is executed. Level 0 defines all the files in file
system. When a level is assigned, all files equal to and
less than that level in file system are backed up. The
time-stamp tells the dump or rdump process when file system
had its last backup. This time-stamp is written by
the dump or rdump process after the specified file system
backup is completed. When there is no time-stamp, the
dump or rdump process assumes the beginning of time
(called the Epoch).
The /etc/dumpdates file is written in ASCII and consists
of a single record per line. This file may be edited to
change any record field, when necessary.
Either process requires operator intervention when any of
the following conditions occur: end-of-tape, end-of-dump,
tape-write error, tape-open error, or when the number of
disk-read errors is greater than 32. In addition to alerting
all operators specified by the -n key, these processes
interact with an operator at the terminal from which dump
or rdump was invoked when either program can no longer
proceed.
All queries written to standard output by the dump or
rdump process must be answered by typing yes or no on the
invoking terminal.
Because a dump to any storage medium requires excessive
time to process, each process checks itself at the start
of each storage volume. In many instances, the default
dump performance can be improved by modifying the number
of blocks per write. For additional information, see the
description for the -b switch in the OPTIONS section.
When a volume write fails, dump or rdump restarts itself
from the last successful checkpoint, with operator permission,
after the currently written storage medium is properly
removed and another (replacement) storage medium has
been mounted.
These processes also tell an operator what is going on at
periodic intervals when writing to the storage medium.
This information consists of somewhat conservative estimates
for the number of blocks to write, the number of
storage media that must be used for the dump, the time to
complete the dump, and the time until the storage medium
must be replaced with another one to complete the dump.
Output is verbose, so that others know that the terminal
controlling dump is busy. When processing takes place,
the following conditions apply:
Fewer than 32 read errors during a dump or rdump tape-dump
process are ignored. Each renewal of the storage medium
requires a new dump process, so that parent processes for
storage media already written are in effect until the
entire storage medium is written. When the dump command
has the W or w key set, no records are written to the
standard output for a file system that has no current
record in the /etc/dumpdates file, even when listed in the
/etc/fstab file. When no argument is specified, the key
operand is assumed to be -9u so that the default file system
is dumped to a default storage medium named
/dev/tape/tape0_d0 (usually a tape).
dump
The dump command copies to the default /dev/tape/tape0_d0,
or to the alternate storage device specified with the -f
option, all files changed after a certain date in the
specified local file system.
rdump
The rdump command copies to the dump_file storage device
all files changed after a certain date in the specified
file system. This command is similar in operation to
dump, except that the -f option is always specified (see
the OPTIONS section) together with any otherkey you may
wish to specify. The dump_file operand should always be
specified by machine name and device name as
machine:device name. If you want to specify an IPv6
address for machine, you must prefix the address with the
\[ (backslash, left bracket) characters and terminate the
address with the \] (backslash, right bracket) characters.
The rdump command starts remote server /usr/sbin/rmt or
/etc/rmt on the client machine to access the storage
medium.
Another vendor's rdump command may fail because rmt is not
located in /etc. To avoid this problem, it may be necessary
to provide a symbolic link on the machine pointing to
/usr/sbin/rmt, as shown in the following example: ln -s
/usr/sbin/rmt /etc/rmt
Although the rdump command can detect magnetic tape on
remote ULTRIX and Tru64 UNIX systems, it cannot detect
magnetic tape on other remote systems. Instead, it
defaults to treating the output medium as a disk file and
aborts the operation should it encounter overflow or I/O
error cases.
Remote systems must be able to run the uname command if
you are to use the rdump command. If a remote system cannot
run the uname command, you can set the environment
variable OSF_RDUMP_SIMP_RCMD before you attempt the operation.
Estimates for dump and rdump.
The information in this note is specific to supported
tape devices and the densities and sizes
they use under rdump. The size and density information
is used to estimate the number of volumes
required for the current dump or rdump request.
Some of the factors that will effect the estimate
calculation include the following: Track format
Compression Interrecord gap size Writing optimization
technologies Appending to a tape
The estimate calculation does not take these factors
into account and can result in very large
(100-500%) miscalculations. The estimates can be
customized by adjusting the size in feet (-s) or
size in 1024-byte block (-BS) variables to the
desired results. The default values for
/dev/tape/tape?_d0 devices used in the dump estimate
calculation are shown in the following table:
Tape Device Density Size Size
(bpi) (feet) (1024-byte
blocks)
TA78 6250 1925 141056
TA79 6250 1925 141056
TA81 6250 1925 141056
TA90 38000 436 194560
TA91 38000 436 194560
TF30 6667 1182 92416
TF70 10000 2457 287948
TF70L 10000 2457 287948
TK50 6667 1182 92416
TK70 10000 2457 287948
TKZ09 54000 7456 4718592
TLZ04 61000 1584 1132646
TLZ06 61000 2640 1887436
TLZ07 61000 2640 1887436
TS05 1600 2075 38912
TU77 1600 2075 38912
TU78 1600 2075 38912
TU80 1600 2075 38912
TU81 1600 2075 38912
TU81E 1600 2075 38912
TZ05 1600 2075 38912
TZ07 1600 2075 38912
TZ30 6667 1182 92416
TZ85 42500 4925 2453299
TZ857 42500 4925 2453299
TZK08 54000 3276 2073600
TZK10 16000 2580 483840
The rdump command starts the remote server
/usr/sbin/rmt on the client machine to access the
storage medium. If the rdump command cannot find
/usr/sbin/rmt, it will try /etc/rmt and rmt. The
rdump program can detect remote tape support on
Tru64 UNIX and ULTRIX systems. However, due to the
lack of a standard for UNIX magnetic tape functions,
it cannot utilize remote tape support on
other systems. This means that multivolume dumpsets
can only be created when the remote system is Tru64
UNIX, DEC OSF/1 (the former name of Tru64 UNIX), or
ULTRIX, or if there is embedded multivolume support
in the remote system (such as is the case with VMS,
where support is in the Magtape ACP). For rare
cases where the remote system is non-UNIX, compatibility
may require that rdump not use UNIX-like
commands. In order to obtain this behavior, the
user or system manager should use the following
command: setenv OSF_RDUMP_SIMP_RCMD
The previous command can be used on a system wide
(global) or per rdump command basis. For proper
operation, the server's /.rhosts file must contain
the name or reference designation of the client's
machine. The rdump and the dump commands do not
handle MFS or AdvFS filesystems. After encountering
tape write errors, dump or rdump queries the
operator about performing a rewrite. If the operator
requests a rewrite, a rewind is performed, followed
by an attempt to rewrite the data. In the
event the no-rewind device is used, the user should
always load a new tape to avoid the possibility of
overwriting previously written archives.
The dump and rdump commands exit with 0 status on success.
Startup errors are indicated with an exit code of 1;
abnormal termination is indicated with an exit code of 3.
To perform a full level 0 dump, enter a command similar to
the following: dump -0un -f /dev/tape/tape1_d0 -b 32 /fs1
In this example, 0 specifies that all files in the
file system fs1 will be dumped to
/dev/tape/tape1_d0; u specifies dump to update the
/etc/dumpdates file after a successful dump of the
file system; and n specifies that operators will be
notified. The estimate calculation will be based
upon the tape device defaults. The write block
size is set to 32 kilobytes. To dump a local file
system to a remote storage tape, enter a command
similar to the following: rdump -3u -f
tape_server:/dev/tape/tape1_d0 /fs1
In this example, 3 specifies the dump level of all
files in the file system /fs1 that will be dumped
to tape /dev/tape/tape1_d0 on system tape_server,
and u specifies the dump to update the /etc/dumpdates
file after a successful dump of the file
system. The estimated calculation will be based on
the rdump defaults. The write block size will be
the default. To obtain an estimated number of
blocks and volumes for the current dump session,
enter the following: dump -0Ef /dev/tape/tape1_d0
/usr
The system displays output similar to the following:
358696 blocks, 0.19 volumes The following
examples show alternative ways of scheduling backups.
Select the backup schedule that best fits your
needs. 7-day incremental schedule
The following schedule is a 7-day incremental
schedule. This schedule is useful for small-tomedium
storage systems. The basic algorithm is n,
n+1, ... The number of dump files to perform a
full restore can vary from 1 to 7. The following
is an example of a 28-day schedule: 0 1 2 3 4
5 6
0 1 2 3 4 5 6
0 1 2 3 4 5 6
0 1 2 3 4 5 6 7-day alternative differential
schedule
The following schedule is a 7-day alternative differential
schedule. This schedule is useful for
small-to-medium storage systems. The basic algorithm
is n-1, n+3, ... The number of dump files to
perform a full restore can vary from 1 to 4. The
following is an example of a 28-day schedule:
0 5 4 7 6 9 8
0 5 4 7 6 9 8
0 5 4 7 6 9 8
0 5 4 7 6 9 8 28-day alternative differential
schedule
The following schedule is a 28-day alternative differential
schedule. This schedule is useful for
small-to-large storage systems. The algorithm combines
the 7-day incremental and the 7-day alternative
differential schedules. The number of dump
files to perform a full restore can vary from 1 to
7. The following is an example of a 28-day schedule:
0 5 4 7 6 9 8
1 5 4 7 6 9 8
2 5 4 7 6 9 8
3 5 4 7 6 9 8
This schedule limits full dumps to once a month.
Therefore, it is possible to lose a month's worth
of data. Alternative approaches to address this
problem might include duplicating the full tape or
doing full backups twice a month instead of once a
month.
The dump command path in single user mode. The dump command
path in multiuser mode. Used by the rdump remote
tape access program. Contains a list of file systems that
were backed up, the date that each file system was backed
up, and the backup level.
Commands: restore(8), rrestore(8), rmt(8)
Files: acl(4), proplist(4)
dump(8)
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