vdump - performs full and incremental backups on mounted filesets
/sbin/vdump [-0..9] [-CDNUquv] [-F num_buffers] [-T tape_num] [-b size] [-f device] [-x num_blocks] fileset
Displays usage help for
Displays the current version of
Displays the filesets that have not been backed up within
Specifies the backup level. The value
for this option causes the entire fileset to be backed up to the storage device.
The default backup level is
Compresses the data as it is backed up, which minimizes the
Performs a level 0 backup on the specified subdirectory.
This option overrides any backup level specification in the command. If this
option is specified, the AdvFS user and group quota files and the fileset
quotas are not backed up.
Does not rewind the storage device, when it is a tape.
Does not unload the storage device, when it is a tape.
Displays only error messages; does not display information
a timestamp entry from the beginning of the backup.
Displays the names of the files being backed up.
Specifies the number of in-memory buffers to use. The valid
2 through 64 buffers;
the default is 8 buffers. The size of the in-memory buffers is determined
by the value of the
Specifies the starting number for the first tape. The default
number is 1. The tape number is used only to prompt the operator to load another
tape in the drive.
Specifies the number of 1024-byte blocks per record in the
The valid range
is 1 through 64 blocks; the default is 60 blocks per record. The value of
this option also determines the size of the in-memory buffers.
Specifies the destination of the saveset, which can be a device,
a file, or, when the - (dash) character is specified, standard
Specifies an ``exclusive or'' (XOR) operation each
time the blocks specified by
to the saveset. The XOR operation is performed on the blocks and the results
written to the saveset as an XOR block that immediately follows the blocks.
Subsequently, you can use the
command to recover
one of the blocks in the group should a read error occur. The valid range
is 1 through 32 blocks; the default is 8 blocks. Using the
option creates larger savesets and increases the amount of time required to
back up a file system, but offers additional protection from saveset errors.
Specifies the full path name of a mounted AdvFS fileset
backed up. Alternatively, specifies a mounted NFS or UFS file system. When
used with the
option, specifies a subdirectory.
The vdump command backs up files from a single mounted fileset or clone fileset to a local storage device. The vdump command is the backup facility for the AdvFS file system. However, the vdump command is file-system independent, and you can use it to back up other file systems, such as UFS and NFS.
The vdump command backs up all files in the specified fileset that are new or changed since a certain date and produces a saveset on the storage device. The date is determined by comparing the specified backup level to previous backup levels recorded in the /etc/vdumpdates file. The default storage device is /dev/rmt0h. You can specify an alternate storage device by using the -f option.
The vdump command performs either an incremental backup, level 9 to 1, or a full backup, level 0, depending on the desired level of backup and the level of previous backups recorded in the /etc/vdumpdates file.
Note that an incremental dump only captures the files that have changed, ignoring all others. This means that if you perform a level 0 dump and a later incremental dump, deleted files are not marked as gone (deleted). If you then do a complete restore with a level 0 saveset and incremental backups, the deleted files will be restored. You must then delete these files individually.
The vdump command backs up all files that are new or have changed since the latest backup date of all backup levels that are lower than the backup level being performed. If a backup level that is lower than the specified level does not exist, the vdump command initiates a level 0 backup. A level 0 backup backs up all the files in the fileset.
After the backup operation is complete, you can use the vrestore -t command to verify that the backup contains the files you wanted to save. The vrestore -t command lists the name and size of each file in the saveset without restoring them.
When you specify the -C option, the vdump command backs up the files with compression. You cannot specify the compression ratio, it is determined by the contents of the dump.
When you specify the -u option, the vdump command enters a time-stamp entry of that fileset and its backup level into the /etc/vdumpdates file.
If a file-system entry with a specific backup level does not already exist in the /etc/vdumpdates file, the vdump command appends the file with a new vdump record; otherwise, the vdump command overwrites the existing record, changing the backup date to reflect the most current backup session. This occurs after all files in the named fileset have been successfully backed up.
The vdump and vrestore commands save and restore AdvFS sparse files. However, sparse files that have been striped are still handled in the fashion of releases earlier than DIGITAL UNIX Version 4.0D: they are allocated disk space and filled with zeros.
You do not have to be the root user to use the vdump command. The AdvFS quota files and fileset quotas in the fileset are included in a saveset when you are the root user and a full fileset is saved. AdvFS quota files and fileset quotas can only be backed up for locally-mounted filesets.
Under normal usage, the
command uses a small
amount of additional space on the storage device, typically less than 1 percent,
when a fileset is backed up. If the
option is used, the
amount of additional space used to back up the fileset increases.
The vdump command does not back up filesets that are not mounted.
Filesets backed up by using the vdump command must be restored by using the vrestore command. The vdump command is not interchangeable with the dump command. Similarly, the vrestore command is not interchangeable with the restore command.
The vrestore command in versions earlier than DIGITAL UNIX Version 4.0 cannot be used to restore savesets produced by the vdump command in DIGITAL UNIX Version 4.0 or higher systems.
The /etc/vdumpdates file is written in ASCII and consists of a single record per line. You must be the root user to update this file or to change any record field.
If you edit the /etc/vdumpdates file, be certain that all records follow the correct format. An incorrectly formatted record in this file may make the file inaccessible for updates or reads.
A typical /etc/vdumpdates file includes entries like the following, defining the fileset name, last backup level, and date:
Contains a list of filesets that were backed up, the date
that each file system was backed up, and the backup level.
Contains the full path names and mount points of filesets.
vrestore(8), mount(8), umount(8)