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How do I
backup my Exchange 2000/2003 server?
One of the most
important tasks for an Exchange
administrator is the regular,
day-by-day, backing up of all the
Exchange databases. This can be easily
accomplished by use of the built-in
NTBACKUP.EXE software found on your
Exchange 2000/2003 server.
Some administrators
might choose to your 3rd-Party backup
tools, such as:
However, as stated
above, you do NOT need to buy expensive
3rd-Party tools just to backup your
Exchange server.
Generally, you can
backup Exchange 2000/2003 in 2 ways:
Online backup and Offline backup.
Online Backup -
An Online backup is performed while the
Information Store is still mounted and
the Exchange server is operational. The
Exchange is Online and available for
transactions, therefore it still allows
users to work without interruption.
Online backups also automatically clear
the database logs upon completion.
Another major
advantage of the Online backup method is
the fact that the Exchange store is
checked for corruption at the
file-system level. This check is done by
verifying the checksums on each 4 KB
(Kilobyte) block or page in the
database. If there is a checksum
failure, backup will terminate. Exchange
will not allow you to back up an
Exchange store with a wrong checksum in
it.
Therefore, after an
online backup is complete, you should
check the Event Viewer to find out
whether your Exchange store is
corrupted. If you see a failed backup
with a page read error event in Event
Viewer, this may be an early indication
of a problem in the database.
Offline Backup -
Offline backup is performed by shutting
down the Exchange Information Store
service and performing COPY procedures
on the Exchange databases (Public Folder
or Mailbox stores). Using an Offline
Backup provides a method to restore the
Exchange system to its last known state
or specific "point in time", and is
usually considered to be less attractive
than the Online backup.
However, you may need
to perform an Offline backup in the
following situations:
- Your Online
backup failed. You can complete an
Offline backup in situations where
an Online backup might fail (for
example, due to an error such as a
checksum1018
JET_errReadVerifyFailure).
- Your backup
software does not support Exchange
Online backup APIs, requiring you to
dismount the Exchange 2000/2003
mailbox and public folder stores
before you backup the server.
Some disadvantages to
performing an Offline backup include:
- You must stop IS
services (You do not need to stop
the IS if you only want to backup
the store, for that you can simply
just dismount it. However if you
want to backup the log files you do
need to stop the IS service).
- Users will not be
able to access their mailboxes
during the offline backup.
- Log files that
contain transactions already written
to the database files will not be
purged after the completion of the
backup.
- The database is
not checked for corruption during an
Offline backup. You might have a
corrupt database and backup sets
that cannot be used to restore your
server to full functionality.
- An increased
chance of data loss due to files
being copied to and from a backup
location.
In this article I will
discuss the Online backup method. |
