Answer
# 5 |
Exchange Backups that Microsoft Supports
The following are the Microsoft® Exchange backups that
Microsoft supports:
Online backups
Offline backups
Online Backups and Types of Online Backups
Online backups are backups done while Exchange services are
running. None of the Exchange services have to be stopped
for this backup to complete.
Online backup does not mean that you try to back up
Exchange database files and Exchange folder structure while
Exchange services are running. Online backup means backing
up a separate Microsoft Exchange or Microsoft Exchange
Server object that is available in backup software. You can
do an online backup using Backup if you install Exchange
administrator or Exchange System Manager in Exchange 2000
Server on a server that will do a backup. If you use third-
party backup software, you have to install the Exchange
Agent or Exchange-aware backup software. Agents are popular
because they extend the functionality of third-party backup
software. You will be backing up Exchange Directory
(Exchange Server version 5.5) or Microsoft Exchange
Information Store service objects. You will not be able to
select individual files to back up or select individual
mailboxes that need to be backed up.
If you try to back up actual Exchange Server files and
folders while services are running, backup will complete
but with files that are skipped. Database files are skipped
because the Exchange database engine has opened them, and
only one program can have exclusive access to a single file
on the disk. If disaster strikes and this is the only type
of backup available, it is possible that Exchange
information will not be recoverable.
When backing up Exchange Server databases, there are four
backup types available:
Normal (or Full) The normal backup process backs up the
directory or Exchange store in its entirety, as well as the
log files. To restore from a normal backup, only one normal
backup is needed. A normal backup marks the objects it has
backed up so that incremental and differential backups have
context. This is accomplished by backing up the entire
database and all the log files, and then purging the log
files.
Copy The copy backup is the same as a normal backup
except no marking takes place to give incremental and
differential context. This means that performing an
incremental backup after a copy backup is equivalent to
performing it before a copy backup. Use a copy backup to
get a full backup of the directory or Exchange store
without disturbing the state of ongoing incremental or
differential backups.
Incremental An incremental backup backs up the subset of
the component that has changed since the last normal or
incremental backup. Then it marks these objects as backed
up. To restore from incremental backups, each incremental
backup since the last normal backup and the normal backup
are needed. An incremental backup backs up only the log
files, and then purges them.
Differential A differential backup backs up changes in
the directory or Exchange store that have occurred since
the last normal backup. To restore from differential
backups, one differential backup and one normal backup is
required. A differential backup backs up only the log files
but does not purge them.
Note:
In few cases, performing a differential or incremental
backup is disabled, for example, immediately after an
offline defragmentation or while circular logging is
enabled.
To restore an online backup in Exchange 2000 Server, you
need the Microsoft Exchange Information Store service
running, and the stores that are being restored need to be
dismounted. To restore an online backup in Exchange Server
5.5, you need to have the Microsoft Exchange System
Attendant service running.
Offline Backups
Offline backups are backups of Exchange files and folders
when Exchange services are not running. If services are not
running, backup software can have exclusive access to
database files and can back them up.
Planned offline backups will result in consistent database
files. When Exchange services are being gracefully shut
down, all transactions are being committed to the database.
Resulting databases will be consistent, marked consistent
or clean shutdown, depending on what version of Exchange
you are running.
Unplanned offline backups are backups that are taken when
the server fails. Database files are copied to some
location because that is the only type of backup available.
If Exchange Server fails before this backup, databases do
not have to be consistent, so they might need repair after
the restore procedure. Make sure to check if the backup was
before or after the failure or Exchange Server problem.
Exchange Backups that Microsoft Does Not Directly Support
For backup methods that are not supported, there is no
guarantee that the methods will work. You should contact
your third-party backup software or hardware vendor in case
of problems with backup. The backup vendor should be the
primary source of support in the case that any of the
following backups are used. Microsoft will work with any
customer that has any backup type. However, if the backup
was created by one of the following methods, the only help
that Microsoft might be able to provide is disaster
recovery, which might involve data loss.
Open File Agent Backups
There are third-party backup programs that use special ways
to do a file-level backup of files that are already opened
by some other application, such as Exchange Server. This
might or might not work. In most cases, it will not work
for Exchange. There is no guarantee that this type of
backup will back up all mailbox and public folder data, and
that you will be able to recover from disasters such as
this. Open file agent backups, in most cases, back up
inconsistent databases.
Mailbox (Brick) Level Backups
There are several third-party backup programs that can back
up and restore individual mailboxes, rather than whole
databases. Because those backup solutions do not follow
Microsoft backup guidelines and technology, they are not
directly supported.
There are known problems with some versions of mailbox-
level backup programs including loss of free/busy data and
incomplete restores. Every effort is made to help, and to
look at the errors and issues that you are having with this
type of backup and restore, to determine if there are
Exchange problems documented that could cause this error.
Snap or Snapshot and Hot Split Backups
This type backup provides benefits somewhat in between
offline and open file agent backups. These backups are
typically done on a hard disk instead of tape devices,
which allows much faster transfer rates.
|
| Vasa
|
Answer
# 6 |
Normal (or Full) The normal backup process backs up the
directory or Exchange store in its entirety, as well as the
log files. To restore from a normal backup, only one normal
backup is needed. A normal backup marks the objects it has
backed up so that incremental and differential backups have
context. This is accomplished by backing up the entire
database and all the log files, and then purging the log
files.
Copy The copy backup is the same as a normal backup
except no marking takes place to give incremental and
differential context. This means that performing an
incremental backup after a copy backup is equivalent to
performing it before a copy backup. Use a copy backup to
get a full backup of the directory or Exchange store
without disturbing the state of ongoing incremental or
differential backups.
Incremental An incremental backup backs up the subset of
the component that has changed since the last normal or
incremental backup. Then it marks these objects as backed
up. To restore from incremental backups, each incremental
backup since the last normal backup and the normal backup
are needed. An incremental backup backs up only the log
files, and then purges them.
Differential A differential backup backs up changes in
the directory or Exchange store that have occurred since
the last normal backup. To restore from differential
backups, one differential backup and one normal backup is
required. A differential backup backs up only the log files
but does not purge them.
|
| Suresh.rajaram
|
along with your userid / name. ThanQ
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