OSF  —  Environment_Note_Added

NAME

dump, rdump  − Performs incremental file system dumps

SYNOPSIS

/usr/sbin/dump [key [argument ...] filesystem]

/usr/sbin/rdump -f dump_file [otherkey [argument ...] filesystem]

The dump command copies to the default /dev/rmt0h, or to the alternate storage device specified with the -f flag, all files changed after a certain date in the specified local filesystem.  rdump

The rdump command copies to the dump_file storage device all files changed after a certain date in the specified filesystem. 

DESCRIPTION

The dump and rdump commands are used to dump local files from a single file system defined by the filesystem parameter to a local or remote storage device, respectively, where filesystem 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 filesystem.  However, the rdump command requires that the -f flag be used with any otherkey and the special dump_file parameters. 

Both commands copy all files in filesystem 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 parameters specify one or more various options that may be used to write files to the storage medium.  Characters permitted by the key parameter are similar to flags 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 parameter specifies other options that tell these dump and rdump processes what to do.  These options are described under FLAGS.  Not all keys permit argument options to be specified. 

The /etc/dumpdates file consists of 3-column record lines that specify the filesystem name, a dump level, and a standard timestamp.  These processes enter a timestamp into the filesystem record after each file in the named filesystem is successfully backed up.  The 3-column record in the /etc/dumpdates file contains the following information:

1  File system name
Lists the filesystem device name. 

2  Dump level
This is an integer between 1 and 9 that defines a hierarchy for files in filesystem.  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 filesystem.  When a level is assigned, all files equal to and less than that level in filesystem are backed up. 

3  Timestamp
The timestamp tells the dump or rdump process when filesystem had its last backup.  This timestamp is written by the dump or rdump process after the specified filesystem backup is completed.  When there is no timestamp, 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 these conditions occur: end-of-tape, end-of-dump, tape-write error, tape-open error, and 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 to the standard input. 

Because a dump to any storage medium requires excessive time to process, each process checks itself at the start of each storage volume.  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 filesystem that has no current record in the /etc/dumpdates file, even when listed in /etc/fstab file. 

       •When no argument is specified, the key parameter is assumed to be -9u so that the default file system is dumped to a default storage medium named /dev/rmt0h (usually a tape). 

dump

The dump command copies to the default /dev/rmt0h, or to the alternate storage device specified with the -f flag, all files changed after a certain date in the specified local filesystem. 

rdump

The rdump command copies to the dump_file storage device all files changed after a certain date in the specified filesystem. This command is similar in operation to dump, except that the -f flag is always specified (see Flags) together with any otherkey you may wish to specify.  The dump_file parameter should always be specified by machine name and device name as machine:device name. 

The rdump command starts remote server /usr/sbin/rmt on the client machine to access the storage medium. 

The dump command exits with 0 status on success.  Start up errors are indicated with an exit code of 1; abnormal termination is indicated with an exit code of 3. 

FLAGS

-0-9Specifies the dump level.  All files modified since the last timestamp whose names are currently stored in the /etc/dumpdates file for a named filesystem 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. 

-b blocks_per_write
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).

-cThe dump medium is a non-9-track cartridge tape. 

-d densitySpecifies the write density of the storage medium.  The density parameter 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 Digital base system supported devices.  Otherwise, the default write density for the dump and rdump commands is 1600 bpi.  Refer to the ENVIRONMENT NOTES section for additional information. 

-f dump_fileWrites 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/nrmt∗, the dump process will enable the -N flag.  When the rdump command is invoked, the dump_file parameter must specify both the remote machine and the storage device in the format machine:device, where machine is the name or reference designation of the host machine and device is the name or reference designation of the storage device. 

-nNotifies, 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). 

-s sizeSpecifies the size of a dump tape.  The size parameter 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 flag). For the dump command, the density will be automatically provided by Digital base system supported devices.  Otherwise, the default tape size for the dump and rdump commands is 2300 feet.  Refer to the ENVIRONMENT NOTES section for additional information. 

-uWrites the time of the beginning of the dump as the timestamp entry in the /etc/dumpdates file for the filesystem record when the dump successfully completes. 

-wTells 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 filesystem listed in the /etc/dumpdates file. 

-BSpecifies a block-mode device.  For the dump command, the estimate calculations will be based on the device’s storage capacity instead of density and size.  Refer to the ENVIRONMENT NOTES for additional information. 

-NTells the operator not to rewind a tape.  This is the  default if the dump_file parameter is /dev/nrmt∗. 

-S full_tape_size
Specifies output file size in feet.  When the -B flag is used, the full_tape_size parameter specifies the output file size in number of 1024-byte blocks. 

-T tape_number
Specifies tape number, which is used in the dialog with the operator as the number of the first tape.

-WSimilar to -w, but for any filesystem listed in the /etc/dumpdates file, prints an output record and highlights this record with the character > (greater than), all files that must be dumped.  When -W is specified, all other options are ignored, and dump exits immediately. 

EXAMPLES

     1.To perform a full level 0 dump, enter a command similar to the following:

dump -0un -f /dev/rmt1h -b 32 /fs1

In this example, 0 specifies that all files in the filesystem fs1 will be dumped to /dev/rmt1h; u specifies dump to update the /etc/dumpdates file after a successful dump of the filesystem, 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. 

     2.To dump a local file system to a remote storage tape, enter a command similar to the following:

rdump -3u -f tape_server:/dev/rmt1h /fs1

In this example, 3 specifies the dump level of all files in the filesystem /fs1 that will be dumped to tape /dev/rmt1h on system tape_server and u specifies dump to update the /etc/dumpdates file after a successful dump of the filesystem.  The estimate calculation will be based on the rdump defaults.  The write block size will be the default. 

     3.A common level scheduling algorithm is the Tower of Hanoi algorithm because it optimizes dump tape usage.  The dump level sequence using this algorithm is as follows:

3 2 5 4 7 6 9 8 9 9    3 2 5 4 7 6 9 8 9 9   ...

The sequence 3 2 5 4 7 6 9 8 9 9 is used for a daily tape dump.  This sequence specifies a set of 10 tapes per dumped file system and is used on a cyclical basis.  Each week, a level 1 dump is taken and the daily Hanoi sequence repeats with 3. 

     4.For weekly tape dumps, a set of 5 tapes per dumped file system is also used on a cyclical basis.  Each month a level 0 dump is taken on a set of fresh tapes that is saved forever. 

     5.To dump a local file system to a remote storage tape, enter a command similar to the following:

rdump -3u -f tape_server:/dev/rmt0h filesystem

FILES

/sbin/dumpThe dump command with static libraries. 

/usr/sbin/dumpThe dump command with shared libraries. 

/usr/sbin/rmtUsed by the rdump remote tape access program. 

ENVIRONMENT NOTES

This section describes system features that are not generic to OSF/1 but that are provided in this OSF/1 implementation. 

Digital Extensions

The following table lists specific tape devices and the densities and sizes they use under rdump:

     1.Estimates for dump and 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

       •Inter-record 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 (-s) or full_tape_size (-BS) variables which values that yield the desired results.  The default values for /dev/rmt∗h devices used in the dump estimate calculation are shown in the following table:

     2.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. 

     3.For proper operation, the server’s /.rhost file must contain the name or reference designation of the client’s machine. 

RELATED INFORMATION

Commands: restore(8), rrestore(8), rmt(8)