vdump(8) System Manager's Manual vdump(8)
NAME
vdump, rvdump - Performs full and incremental backups on filesets
SYNOPSIS
/sbin/vdump -h
/sbin/vdump -V
/sbin/vdump [-w]
/sbin/vdump [-0..9] [-CDNPUquv] [-F num_buffers] [-T tape_num] [-b size] [-f device] [-x num_blocks] fileset
/sbin/rvdump -h
/sbin/rvdump -V
/sbin/rvdump -w
/sbin/rvdump [-0..9] [-CDNUquv] [-F num_buffers] [-T tape_num] [-b size] [-f nodename:device] [-x num_blocks] fileset
OPTIONS
Specifies the number of 1024-byte blocks per record in the saveset. The valid range is 2 through 64 blocks; the default is 60 blocks per
record. The value of this option also determines the size of the in-memory buffers. Compresses the data as it is backed up, which mini-
mizes the saveset size. 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. Specifies the
destination of the saveset.
For vdump, the local destination can be a device, a file, or, when the - (dash) character is specified, standard output.
For rvdump, the mandatory specification is nodename:device to specify the remote machine name that holds the device or file. Spec-
ifies the number of in-memory buffers to use. The valid range is 2 through 64 buffers; the default is 8 buffers. The size of the
in-memory buffers is determined by the value of the -b option. Displays usage help for the command. Does not rewind the storage
device when it is a tape. Produces backward-compatible savesets that can be read by earlier versions of the vrestore command. How-
ever, some data, such as very large quota limits, can be lost in such a saveset. Displays only error messages; does not display
information messages. 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. Updates the /etc/vdumpdates file with a timestamp entry from the beginning
of the backup. Does not unload the storage device when it is a tape. Displays the names of the files being backed up. Displays
the current version of the command. Displays the filesets that have not been backed up within one week. Specifies an "exclusive
or" (XOR) operation each time the blocks specified by num_blocks are written 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, the vrestore com-
mand can use this block 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 -x 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 backup level. The value 0 for this option causes the
entire fileset to be backed up to the storage device. The default backup level is 9.
OPERANDS
Specifies the full path name of a mounted AdvFS fileset to be backed up. Alternatively, specifies a mounted NFS or UFS file system. When
used with the -D option, specifies a subdirectory.
DESCRIPTION
The vdump command backs up files and any associated extended attributes (including ACLs, see the proplist(4) and acl(4) reference pages)
from a single mounted fileset or clone fileset to a local storage device.
The rvdump command backs up files and any associated extended attributes (including ACLs, see the proplist(4) and acl(4) reference pages)
from a single mounted fileset or clone fileset to a remote storage device.
The vdump and rvdump commands are the backup facility for the AdvFS file system. However, the commands are file-system independent, and you
can use them to back up other file systems, such as UFS and NFS.
The commands back up all files in the specified fileset that are new or changed since a certain date and produce 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 for the vdump command is /dev/tape/tape0_d1. You can specify an alternate storage device by using the -f option.
There is no default storage device for the rvdump command; it must be specified.
The commands perform 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 commands back 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 commands initiate 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. This command lists the name and size of each file in the saveset without restoring them.
When you specify the -C option, the commands back up the files with compression. You cannot specify the compression ratio, it is deter-
mined by the contents of the dump.
When you specify the -u option, the commands enter 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 commands append the file with a
new vdump record; otherwise, the commands overwrite the existing record, changing the backup date to reflect the most current backup ses-
sion. This occurs after all files in the named fileset have been successfully backed up.
Archives that were created prior to Tru64 UNIX Version 5.0 will be restored with the same characteristics they would have if they were
restored on the earlier systems. For example, any UFS sparse files archived with the vdump command prior to Tru64 UNIX Version 5.0 will be
allocated disk space and filled with zeros and any AdvFS striped sparse files archived with the vdump command prior to Version 4.0D will be
allocated disk space and filled with zeros.
You do not have to be the root user to use the vdump or the rvdump 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 commands use a small amount of additional space on the storage device, typically less than 1 percent, when a file-
set is backed up. If the -x option is used, the amount of additional space used to back up the fileset increases.
If you use either of the commands to back up a fileset to an output file that is part of the fileset you are backing up, there are two
results you should be aware of: That output file could be twice the size it should be. When you restore that output file, you obtain only
a partial copy of it.
To inform you of the situation, the commands display a message similar to the following: vdump: /demo/vdump.file is on the same device as
/demo, this vdump: could cause recursive back up problems.
vdump: Do you want to abort the dump? (yes or no).
Typically, you would want to abort the backup operation and select another file on which to back up the fileset. However, there may be
situations when you do not want to abort the operation. For example, if you are backing up a portion of a fileset using the -D option, you
can store the resulting output file in the same fileset in a section not being backed up.
RESTRICTIONS
To run the rvdump command, you must be able to execute the rsh command on the remote node to which you are dumping. See rsh(8) for server
and client access rules.
The vdump and rvdump commands do not back up filesets that are not mounted.
Filesets backed up by using the vdump or the rvdump command must be restored by using the vrestore or the rvrestore command. The vdump and
rvdump commands are not interchangeable with the dump and rdump commands. Similarly, the vrestore and the rvrestore commands are not inter-
changeable with the restore and rrestore commands.
The vrestore command in DIGITAL UNIX versions earlier than Version 4.0 cannot be used to restore savesets produced by the vdump command in
DIGITAL UNIX Version 4.0 or higher systems or in Tru64 UNIX systems.
If the vdump and rvdump commands attempt to write to a disk partition that contains a valid disk label, the device driver will not over-
write the disk label. An error is returned by the driver for character devices but not for block special devices, so you must take special
care if you use block special devices. Therefore, if you are dumping to a partition that contains block 0 of a disk, you must first clear
the disk label. If you do not, the vrestore and rvrestore commands interpret the disk label as part of the saveset, resulting in an error.
If your partition does not start at block 0, there is no problem because the vdump and rvdump commands will not attempt to write over the
disk label.
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.
Caution
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.
EXAMPLES
A typical /etc/vdumpdates file includes entries like the following, defining the fileset name, last backup level, and date:
dmn2#set2 8 wed Apr 21 07:40:35 1999 dmn2#set2 9 Thu Apr 22 07:20:42 1999 dmn2#set2 3 Fri Apr 23 07:47:37 1999 dmn2#set2 7 Thu Apr
22 08:23:05 1999 /dev/disk/dsk0g 0 Mon Apr 26 12:11:42 1999
In this example, dmn2#set2 represents an AdvFS fileset; /dev/disk/dsk0g represents a UFS file system. If you perform a level 8
backup of the dmn2#set2, using this /etc/vdumpdates file, you can expect the following results: The vdump command ignores the
/dev/disk/dsk0g entry because it does not match the specified fileset, dmn2#set2. The vdump command ignores the level 8 and 9
entries because these entries are equal to or higher than the level 8 backup you requested. This leaves only the level 3 and 7
entries. Of the two remaining entries, the vdump command chooses the entry with the most recent dump date, which is the level 3
entry. The vdump command backs up all files that were created or modified after the dump date of the level 3 entry. The vdump com-
mand modifies the access time of each file in the fileset. To perform a full level 0 backup of a local fileset to a local device,
enter a command similar to the following: % vdump -0 -u -f /dev/tape/tape1_d6 /fs1
In this example, -0 specifies that all files in the fileset /fs1 will be backed up to /dev/tape/tape1_d6; -u specifies vdump to
update the /etc/vdumpdates after a successful backup of the fileset. To perform a full level 0 backup of a local fileset to a
remote device, enter a command similar to the following: # rvdump -0 -u -f pease:/dev/tape/tape1_d6 /fs1
In this example, -0 specifies that all files in the fileset /fs1 will be backed up to the remote device /dev/tape/tape1_d6 on
machine node pease; -u specifies rvdump to update the /etc/vdumpdates file after a successful backup of the fileset. When the
backup saveset device is the character - (dash), the vdump command writes to standard output. Thus, the vdump and vrestore commands
can be used in a pipeline expression to copy filesets. The following are typical commands; they are equivalent: # vdump -0 -f -
/usr | (cd /mnt; vrestore -x -f -) # vdump -0f - /usr | vrestore -xf - -D /mnt
The rvdump and rvrestore commands are unable to use the character -. The output device must be specified. When using the vdump and
rvdump commands to dump to a disk partition that contains a reference to block 0 of a block special device, you must first clear the
disk label. If you do not, the dump process may appear successful, but the restore will not be: # rvdump -f mantis:/dev/disk/dsk2a
-D /qarun
path : /qarun
dev/fset : qarun#qarun
type : advfs
advfs id : 0x358847e8.00033989.1
rvdump: Date of last level 0 dump: the start of the epoch
rvdump: Dumping directories
rvdump: Dumping 30212891 bytes, 198 directories, 1881 files
rvdump: Dumping regular files
rvdump: Status at Wed Jul 15 18:17:05 1998
rvdump: Dumped 30212891 of 30212891 bytes; 100.0% completed
rvdump: Dumped 198 of 198 directories; 100.0% completed
rvdump: Dumped 1881 of 1881 files; 100.0% completed
rvdump: Dump completed at Wed Jul 15 18:17:05 1998 # rvrestore -xf mantis:/dev/disk/dsk2a -D /tmp rvrestore: unable to use save-
set; invalid or corrupt format For weekly tape backups, a set of 5 tapes per backed up fileset can be used on a cyclical basis.
Each month a level 0 backup is taken on a set of fresh tapes that are saved until the next level 0 backup.
The following is a guideline for the level of backup to perform during weekly, biweekly, and monthly periods:
-------------------------------
M Tu W Th F
-------------------------------
Weekly 0 3 2 5 4
Biweekly 0 3 2 5 4
0 9 8 9 9
Monthly 0 3 2 5 4
1 9 8 9 9
1 3 2 5 4
1 9 8 9 9
-------------------------------
FILES
Specifies the vdump command path. Specifies the rvdump command path. 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.
SEE ALSO
Commands: mount(8), umount(8), rsh(8), vrestore(8), rvrestore(8)
Files: acl(4), proplist(4)
vdump(8)