vdump(8)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 2048 blocks; the default is 60 blocks per
record. The value of this option also determines the size of the in-
memory buffers. The maximum block size cannot exceed the maximum block
size supported by the associated hardware. Compresses the data as it
is backed up, which minimizes 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.
Specifies 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. Use the -N option
when you want to dump more than one saveset to a tape. Produces
backward-compatible savesets that can be read by earlier ver‐
sions of the vrestore command. However, 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
command 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 stor‐
age 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 speci‐
fied.
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 speci‐
fied 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
session. This occurs after all files in the named fileset have been
successfully backed up.
If you use the -N option to vdump more than one saveset to a tape, see
the vrestore command for information on restoring a series of savesets
from a tape.
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.
Under normal usage, the commands use a small amount of additional space
on the storage device, typically less than 1 percent, when a fileset is
backed up. If the -x option is used, the amount of additional space
used to back up the fileset increases because XOR blocks are written.
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.
You do not have to be the root user to use the vdump or the rvdump com‐
mand.
The vdump and rvdump commands back up only mounted filesets.
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 com‐
mands. Similarly, the vrestore and the rvrestore commands are not
interchangeable with the restore and rrestore commands.
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.
The vdump command is disabled on filesets enabled for the Data Manage‐
ment Application Programming Interface (DMAPI). Users should check with
the vendor of their data management (DM) application for the appropri‐
ate back up procedure to use.
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 you want to use the vdump and rvdump commands to write a saveset on
the a or c disk partition, and you have no data on any partitions on
that disk, then you must zero the disk label so vdump can write to par‐
tition a or c starting at block 0. If you have data on any disk parti‐
tions, then use a partition other than a or c. See “Duplicating or
Recovering a System (Root) Disk” in the System Administration.
You can backup to partitions that do not start at block 0 (partition b
for example) if the partition you want to dump to is large enough to
hold the data. For more information about dumping to disk partitions
see AdvFS Administration, Dumping to a File or Disk Partition.
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 fol‐
low 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 Sat Apr 21 07:40:35 2001 dmn2#set2 9 Sun Apr 22
07:20:42 2001 dmn2#set2 3 Mon Apr 23 07:47:37 2001 dmn2#set2 7
Sun Apr 22 08:23:05 2001 /dev/disk/dsk0g 0 Thu Apr 26 12:11:42
2001
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 command 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 (level 0) files in the
fileset mounted at /fs1 will be backed up to /dev/tape/tape1_d6;
-u specifies that vdump will 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
mounted at /fs1 will be backed up to the remote device
/dev/tape/tape1_d6 on machine node pease; -u specifies that
rvdump will 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 com‐
mands; 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 - (dash)
character. The output device must be specified. To dump more
than one saveset on a single tape, enter a command similar to
the following: # vdump -N /dev/tape/tape0 fs1 # vdump -N
/dev/tape/tape0 fs2
In this example, the -N option specifies that the tape will not
be rewound between saving the filesets. For weekly tape back‐
ups, 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)
AdvFS Administration
vdump(8)
