Active databases and open files are typically your most important data. Therefore, it is critical that you employ a data protection solution that natively supports backing up these mission-critical files. Backup solutions that require complex plug-ins or costly third party tools to protect open databases and files, such as Open File Manager (OFM) or Open Transaction Manager (OTM), are vulnerable to serious compatibility and operational problems between the backup solution, the database and the database plug-ins. Such backup solutions are not always compatible with latest release of OFM/OTM. In addition, upgrading a database can cause serious compatibility operational problems between the backup solution, the database and the database plug-ins. Unfortunately most of today's backup solutions require these third party tools to back up open databases and files.
Iron Mountain®'s LiveVault®, an automated server backup and recovery solution, removes risk and complexity through built-in support for backing up open files and databases. LiveVault continuously protects open and changing databases such as Microsoft® Exchange Server, Microsoft® SQL Server, Oracle and Lotus Notes without the need for complex plug-ins or costly third party tools. This is a unique and powerful advantage of LiveVault. This document describes two technologies employed by LiveVault that work together to safely and effectively protect open files and databases:
Individual backup processes are referred to as jobs that transition between two phases: initial backup and continuous or scheduled backup.
The first time a server is configured for backup, an initial LiveVault backup occurs. A copy of each file and directory selected to be backed up is efficiently and securely sent to the vault, creating a baseline image of the files and file structure. The initial backup runs until completion. If the initial backup is interrupted (due to server or network outages) the backup will resume automatically from where it left off (under normal circumstances).When the first copy of all data selected for backup has been replicated to the vault, restore jobs can be successfully run to recover data.
After the initial backup of a file, LiveVault only needs to transfer the changed deltas within the file. Similarly, after the initial synchronization, LiveVault always performs delta backups and never needs to perform another synchronization (Assuming we do not run into any problems, sometimes we request that they rebaseline, and store the old data elsewhere). This enables LiveVault to efficiently back up data 24x7, typically sending changes to data on 15 minute intervals while minimizing network bandwidth usage. Two powerful technologies are used in parallel during the phases described above.
Snapshots are a file system function. They provide an isolated, virtual file system for specific applications (such as backup) to access files as they exist at a moment in time, without having to compete with other applications using those files.
During backup jobs — typically at 15 minute intervals — LiveVault instantiates snapshots. LiveVault uses snapshot technology for two primary reasons:
In practice, when the LiveVault® Agent requests a snapshot, an empty snapshot file is created. After this, if an application modifies a file, a "pre-image" of the blocks of the file being modified are moved to the snapshot file. When LiveVault® then asks for this file, the snapshotter sends LiveVault®'s request for this data to the snapshot file. Once the backup job is complete, LiveVault® deletes the snapshot file.
The Microsoft Filter Driver framework is a well-defined set of programming interfaces developed by Microsoft to allow third party services to interact with actions occurring within the file system. LiveVault uses a file system filter to monitor the changes that occur between snapshots.This way, LiveVault is able to efficiently capture and send just the changed deltas after a snapshot is instantiated. The filter removes the need for LiveVault to scan the file system for each backup job to determine the changes to the file system. This significantly improves the performance of backup jobs (which typically finish in seconds to minutes). Not all Microsoft OS versions include the filter driver framework. When the framework is not present, the scanning process is longer, depending on the number of files and the amount of data in the file system. The LiveVault Agent software scans the file system to identify files and blocks that have changed. For very efficient delta backups using the LiveVault filter you should be running:
Snapshots, by definition, provide complete read access to all files on a system, with no ability to modify them. They are then available to applications using the snapshots. With the filter driver monitoring file system activities, the LiveVault® Agent is able to:
In a 24x7 production environment, many database or application files are always open and actively changing. If the server suffers a power failure and is restarted, one of the functions of the database software is to bring the database into a transactionally consistent state as part of its startup activity by "rolling out" any incomplete transactions. To do this, many databases keep transaction log files as well as the main database files. All modern databases such as SQL, Exchange, Oracle, Sybase and Lotus Notes maintain transactional consistency in their databases.
Backup products typically require either that the database be brought into a quiet state or shut down before backup to ensure that the collection of database files (log files, database files, etc.) is in a consistent state.
In contrast, LiveVault backup does not require that the database be shut down nor does it necessitate any pre- or post-processing or the purchase of database plug-ins. Through its snapshot technology, LiveVault® can guarantee that all the database files are "captured" at a specific instant in time which reflects the ondisk state of all those files at that instant. If the collection of database files is later restored, when the database starts up it will detect files in a state that could have resulted from a power failure or other interruption and, if necessary, will make the database transactionally consistent as part of its startup.
With traditional backup, the normal scheme is to retain a database's transaction log files until after a known good backup has occurred. Often the backup software plug-in must reset the log files or command the database software to do so. Regardless of the method, the size of the log files must be contained so that these files don't eventually fill up the disk.
As it is unnecessary for LiveVault® to interact with database software, the following methods are typically used in conjunction with LiveVault to control log file growth, depending on the database:
Many database packages provide features for handling or assisting with backup. These features can be used in parallel with LiveVault® if so desired. A few typical examples are mentioned below:
Open databases and files are the most difficult to protect — yet they are typically your company's most valuable data assets. LiveVault® helps you overcome this challenge by providing reliable, automated protection of your company's valuable data, including open databases and files. LiveVault®'s unique features provide secure, continuous protection for critical open database applications such as Microsoft® SQL and Exchange, Lotus Notes, Oracle and other core business applications — without the need for third party addons and plug-ins or the extra effort required by more traditional backup solutions.