Backup and recovery enhancements in SQL Server 2005

As with any new software release, you'll often find new features you didn't know existed or you didn't know you needed. Many backup and restore features that exist in SQL Server 2000 will remain the same in SQL Server 2005, but there are several new enhancements worth your consideration.

Mirrored backups

SQL Server 2005 lets you create mirrored backups. A mirrored backup allows you to create two or four identical copies of the backup files in case one of the sets is damaged. The mirrors have identical contents, so you can mix the files in the event that one becomes corrupt.

Say you have mirror set 1 and mirror set 2, both with full backups and transaction log backups. If the full backup for mirror set 1 becomes corrupt, you can do a restore using the full backup from mirror set 2 and then continue using the transaction log backups from mirror set 1.

Online restores

You also have the ability to do an online restore, but, don't get too excited. From the name, it sounds like you can keep the entire database up and running and have users in the database when you do a restore -- but that is not the case. Online restores allow you to restore an offline filegroup while keeping the database online. So you can keep most of your database up and running, but the filegroup you want to restore has to be offline.

Note: To run this feature, you must be using SQL Server 2005 Enterprise Edition, and the primary filegroup cannot be offline. Plus, you have to make sure your application can take filegroups offline and still be able to function. With careful planning this could be very useful, but it will probably not be a feature many people will use. ((Content component not found.))

Copy only backups

A feature I think will get a lot of mileage is copy only backups, which gives you the ability to make a copy in the middle of your backup sequence without disrupting the sequencing of the other backup files. Using SQL Server 2000, if you run a special full backup in the middle of the day, in order to restore, you must use that full backup and any transaction log that occurred after that full backup. This new feature allows you to create a copy only backup and then use your normal full backup for recovery purposes.

For differential backups, there is no change in the way the process works. For transaction log backups, you also have the ability to do copy only backups -- again without disrupting the sequencing of the other backup files. Any backup created using this option is marked as copy_only in the backup tables.

Partial backups

You may think partial backups are the same as differential backups -- but they are not. A partial backup backs up all filegroups except those filegroups marked read only, unless specified. For a read-only database, only the primary filegroup is backed up. If you have a lot of static data in read-only filegroups, this could be a much faster way to back up your database.

Restore from previous versions

One thing that remains the same in SQL Server 2005 is the ability to restore databases from earlier versions; you can restore database backups from SQL 7.0 and 2000. (There is, however, still no way to restore backups from 6.5.)

Note: You have not been able to restore system databases from prior versions, and the same holds true in SQL Server 2005.

I've highlighted several new backup and restore features to investigate with SQL Server 2005. For more information:

Expanding the reach of disaster recovery

Rate this Tip To rate tips, you must be a member of SearchStorage.co.UK. Register now to start rating these tips. Log in if you are already a member. Digg This!     StumbleUpon     Del.icio.us    RELATED CONTENT Backup and disaster recovery Data backup strategies: Migrating from tape to disk Four disaster recovery strategies to consider when using data deduplication Moving bottlenecks in the backup path 8 steps to better data security How to back up virtual machines Troubleshooting automated tape libraries How to choose a Web-based email archiving vendor How to develop a VTL data retention strategy How to conduct a disaster recovery test Outsourcing backup: Get the right service level agreement Remote data protection How far away should backup tapes be stored offsite? Silver Peak CEO warns of Ethernet packet loss during data replication EMC integrates Replication Manager with VMFS SaaS provider turns to Atempo Live Backup for laptop backup Atempo, Nirvanix offer cloud-based file archiving VMware ships Site Recovery Manager DR software SunGard plans cloud-based disaster recovery for VMware EMC Mozy targets Mac backup Dell sees SaaS providing support, systems management FalconStor CDR thrashes IBM at fee-paying school RELATED RESOURCES 2020software.com, trial software downloads for accounting software, ERP software, CRM software and business software systems Search Bitpipe.com for the latest white papers and business webcasts Whatis.com, the online computer dictionary DISCLAIMER: Our Tips Exchange is a forum for you to share technical advice and expertise with your peers and to learn from other enterprise IT professionals. TechTarget provides the infrastructure to facilitate this sharing of information. However, we cannot guarantee the accuracy or validity of the material submitted. You agree that your use of the Ask The Expert services and your reliance on any questions, answers, information or other materials received through this Web site is at your own risk.