The Advanced Open Files Add-on
Important Notice
The information and instructions contained within this document are specific to BackupAssist v3.x.x. While some of this information will be valid for other versions of BackupAssist we do not support the application of any steps or suggestions on versions other than v3.x.x
Documentation specific to BackupAssist v4 will be available very soon and we appologize for any inconvenience.
The Problem With Open/Locked/In-use Files
Active applications will often have files that are continuously in-use or open. When files are in such a locked state, a real problem can be presented when you attempt to perform a backup of these files, as they cannot be accessed by backup applications. As a consequence, these files will not be copied to the required backup media (tape, hard-disk, DVD/CD, etc), leaving your business critical data unprotected.Servers also run critical applications such as databases which store data both in memory and on disk. This makes it very difficult for backup applications to distinguish which data needs to be backed up. If the backup of your database is not synchronised properly and the backup process misses data from either memory or disk, you may be left with a corrupt backup, which is useless when it comes time to perform a restoration.
To overcome this issue, traditionally you can forcefully stop the database to ensure that no files are locked or in-use. This, however, requires users to be taken offline and adds the risk that the database may not start up normally, creating significant hassles and work for system administrators.
For these very troublesome open file problems, Snapshot technology can be used to take a snapshot or 'picture' of the data at a particular instant in time. A backup application can then backup from this snapshot or point-in-time copy, rather than the original data files that may be in-use and locked, and subsequently inaccessible to backup requests.
What does the Advanced Open Files Add-on do?
To overcome the issues of backing up open or locked files, users can opt for the BackupAssist Advanced Open Files Add-on which involves the use of the BackupAssist Snapshot Manager.The BackupAssist Snapshot Manager is an advanced open file management solution which ensures that you have complete protection for all your mission critical data by taking a point-in-time snapshot of your data before commencing the backup.
This ensures that locked, open and in-use business critical data files can be easily backed up without taking users offline or interrupting any systems that are currently in use.
With the Advanced Open Files Add-on, 'skipped file' messages in your backup reports are no longer an issue. Additionally, applications with locked or open files, such as Lotus Notes, Oracle, Office and custom database applications, can all be accessed and backed up whenever required: 24 hours a day, 7 days a week.
Who Needs the Advanced Open Files Add-on?
There are two situations where you would need the Advanced Open Files Add-on:- You are running Windows 2000 Server
- You are running third-party or legacy applications that are not compliant with VSS
The Microsoft VSS or Volume Shadow Copy Service that is built into the Windows Operating System for snap-shots of open files is currently only available through Windows XP and Windows 2003. This means that businesses running Windows 2000 servers cannot use VSS to backup their open files and are consequently at a great risk, with no open file backup protection.
Applications must be VSS compliant in order for the backup application to be able to take a snapshot of any open files. Currently, many business applications are not compliant with the VSS standard, which includes a large number of legacy applications. For applications that are not VSS compliant, VSS only provides crash consistency on files that are open or in use during the backup procedure.
Crash consistency does not guarantee that application transactions (data swapped between memory and disk) will be intelligiently backed up. This means that if an application transaction is in progress at the time of a snapshot, the actual snapshot may only contain a partial record of that transaction, rather than the full and complete transaction. Consequently, the data backed up is incomplete, and you are left with a corrupt backup, which was the situation described earlier in this document.
The BackupAssist Snapshot Manager has the advantage of providing support for legacy and non-VSS compliant applications under any Windows Operating System environment.