Download DLM Chapter 20: DMOLB Online Backup

Chapter 20
DMOLB
Online Backup
DMOLB: Online Backup Utility  749
DMOLB
Purpose:
DMOLB backs up BASIS database files while the database is open. Without the DMOLB
utility, you could only back up BASIS database files if all users were disconnected from
the database. The DMOLB utility temporarily prevents users from updating data in a
database file while it is being backed up.
Note: Only a database administrator can run the DMOLB utility. Also, only databases that
include an FQM model can be backed up.
Operating Systems:
All
Syntax:
UNIX
The dmolb command must be entered in lower case characters. Parameters may be
specified in upper or lower case.
UNIX, Windows
Use a space or comma between each parameter.
VMS
Use a forward slash (/) or comma between each parameter.
dmolb UID=uid UPW=upw DB=database
BACKUP_DIR=directory
{VERSION=0:99}
{SETs=sets}
{WAIT=YES|NO}
{INPUT=infile}
{OUTPUT=outfile}
{COPY_COMMANDS=ccfile}
{VF=vocfile}
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Required Parameters:
The DMOLB utility prompts you for the value of a required parameter that is not
specified on the command line.
UID=uid
(Required)
See Table 11-2.
UPW=upw
(Required)
See Table 11-2.
DB=database
(Required)
The database to be backed up. The database name may be that of an RDB, TDB, or DDB.
Specify the letter X as the first letter of the database name to denote a DDB.
BACKUP_DIR=directory
The directory where the backup copies of the database files are stored. The backup file
name is the same as the original.
Note: If a database file descriptor (as recorded in its DDB) contains a symbol such as a
UNIX or Windows file environment variable or VMS logical name, that symbol must be
defined for the DMOLB utility. For example, the file descriptor for the BASIS BOLD
database on UNIX is $BASIS_DB/dm_bold/idx; the environment variable BASIS_DB
must be defined for the DMOLB utility.
Optional Parameters:
VERSION= 0:99
The database version number. Up to 99 versions (physical databases) may exist for the
same logical database definition. The default value is 0.
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SETs=sets
A list of file sets to be backed up where sets is one of the following values:

* or ALL indicates all sets.

An integer that represents a file set number.

A list of integers that represent file set numbers enclosed in parenthesis. For
example, you specify file sets 1, 3, 4, and 5 using the following: (1, 3, 4, 5) or (1,
3:5). On UNIX platforms, you must enclose the parenthesis in quotes. The DMOLB
utility processes the file sets in the order you specify. You can specify up to 63 file
sets.
The DMDBA utility assigns each database file to a file set. Interdependent files are
assigned to the same set. Independent files are assigned to a separate set. Use the
DMDBA utility's Administration task H to see file-set assignments. The default value for
the Sets parameter is ALL. For a TDB or DDB, ALL or * is the only valid value.
WAIT=YES|NO
If YES, the DMOLB utility waits, if necessary, for protected access to a file set. Protected
access prevents other BASIS users from adding/deleting/modifying documents for views
contained in a file set. The default value is YES.
INPUT=infile
The file from which answers to prompts are to be read. See table 11-3 for the default
value.
OUTPUT=outfile
The file to which prompts and messages are sent. See table 11-3 for the default value.
COPY_COMMANDS=ccfile
The file to which DMOLB writes O/S copy commands that restore the database files from
the backup directory. If the parameter is omitted, the file is not created.
VF=vocfile
The vocabulary file. See table 11-3 for the default value.
752  DMOLB: Online Backup Utility
Description:
The DMOLB utility performs a disk-to-disk copy of database files. It copies every
database file for each specified set from its database directory to the specified backup
directory. The DMOLB utility removes write and delete permission from the backup file.
In order to ensure the files of a file set are static while they are being backed up, DMOLB
starts a transaction, setting a protected-read lock on every view in the file set. DMOLB
waits (if WAIT=YES) until all concurrent user transactions are complete. Once the
protected read transaction starts, DMOLB can copy the files of the file set because
updates to the views by other users are temporarily blocked until the backup completes.
Note:
DMOLB does not provide the capability to copy from disk to tape.
Restoring From Backup
To restore a BASIS database using files created by the DMOLB utility, you copy the files
from the backup directory to the database directory using the operating system copy
command and reinstate write permission. Open Text strongly recommends that you copy
all the files in a file set in order to maintain data integrity.
To assist in the task of restoring from backup, DMOLB provides the parameter
COPY_COMMANDS. Depending on the needs of your site, you can either include the
resultant copy-commands file in a restore procedure/script of your own, or run the copycommands file as it stands.
Journal Management
Journal files cannot be included in DMOLB utility backups because the Kernel has
exclusive control of the active journal file. Once you decide to use the DMOLB utility,
you must back up journal files when the journal files fill up. If you must restore the
database and replay journals, you start the replay with the journal file that was open when
the DMOLB utility ran. Generally, journal replay cannot start from the beginning of the
journal file. Rather, you must start the replay from the date and time at which the
DMOLB utility started. Use the DMJ utility's DATE and TIME parameters to specify the
starting point.
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DMOLB Messages
DMOLB generates informative messages to its output file (specified by the OUTPUT
parameter) to log events during execution. The messages provide the following
information:
 The specific database being backed up and its backup directory
 Summary messages that display the total file size copied (in megabytes), the total
number of files, and the total number of file sets.
For example, the following are the backup messages produced during a backup of the
BOLD database on a UNIX system:
$ echo $BKUP
/idi/local/BASISuser/boldbackup
$ dmolb uid=sauid upw=***** backup_dir=$BKUP db=bold
DMOLB V5 R0
20000516 [9.0]
CS010
20000918 115005 backing up BOLD
to /idi/local/BASISuser/boldbackup/*
20000918 115009 copying
136.7 MB in 2 file(s) of file set 1
20000918 115212
36.7 MB remaining
20000918 115256 totals:
136.7 MB,
2 file(s), 1 file set(s) in BOLD
NORMAL TERMINATION - DMOLB
Interpreting DMOLB Messages

The DMOLB utility translates logical names from any environment variables in the
command to their full path equivalents (for example, $BKUP appears as
/idi/local/BASISuser/boldbackup).

The DMOLB utility displays the message MB remaining after increments of 100
MB.

You can determine the duration of a backup by calculating the time elapsed between
the first and last timestamps in the DMOLB messages.

You can determine how much time elapsed while the utility copied a particular file
set by calculating the difference between adjacent timestamps.

The interval between the "backing up" message and the first "copying" message
represents the time DMOLB consumed looking up information in the DDB.
754  DMOLB: Online Backup Utility
DMOLB Message List
The following table describes each DMOLB utility user error message:
Message Number
Message
UE 32646
Neither SYSA nor XSYSA may be specified as the database.
UE 32655
The required user identifier is missing.
UE 32656
The required user password is missing.
UE 32657
The required database name is missing.
UE 32658
The required backup directory descriptor is missing.
UE 32659
The given backup directory descriptor is invalid.
UE 32660
The given backup directory cannot be opened.
UE 32661
You must specify SETs=ALL to back up a DDB or TDB.
UE 32662
Given file set ** does not exist.
UE 32663
The database has no FQM model.
UE 32664
Given file set ** has more than 100 record types.
UE 32665
No model with the requisite views exists for file set **
UE 32667
A database file descriptor (FD) is not usable, probably because a
logical/symbol embedded in the FD is undefined.
UE 32670
Version ** of the given database does not exist.
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756  DMOLB: Online Backup Utility