One of the most common data loss scenarios on large RAID systems is database corruption. Corrupt databases are either completely unreadable or practically unusable, and businesses often face serious downtime and heavy losses when corruption occurs.
Although many factors can cause database corruption on modern systems, hardware damage is a common and potentially serious contributor. To improve your chances of a successful data recovery, you should understand the role that physical media issues can play in database corruption.
Hardware, Corruption and the Role of Redundancy
Most businesses store databases, email archives and other large files on RAID systems in order to take advantage of RAID redundancy. Redundant systems store all data on at least two local locations, thus avoiding some of the most common sources of data loss.
However, redundant systems can still lose data due to file corruption. Even on an otherwise healthy RAID, database files can become corrupt when a database management application shuts down unexpectedly, causing the RAID to write incorrect or incomplete data. This can result in garbled or unreadable databases.
If a RAID loses a single drive, it may still contain a working set of data depending on the RAID level and configuration. Unfortunately, the chances of file corruption on a RAID system rise significantly after even a single hard drive failure, as bad sectors on the remaining drive can prevent normal access. Data synchronization issues can also occur, especially during the RAID rebuild process.
The good news is that many relational database management systems are specifically designed to minimize the chances of corruption. However, all RDBMS products are designed for functional systems, and physical media issues can certainly test the limits of software.
Avoiding Data Loss Due to Database Corruption
To prevent database corruption, you should find and use an appropriate relational database management system. Never use an RDBMS designed for a small number of users if you have a relatively large workforce accessing your system on a regular basis. Make sure to use up-to-date RDBMS applications and do not put off important updates.
When you need to rebuild your RAID due to a hard drive failure, back up critical database files before starting the process. Perform regular system maintenance and never put off a hard drive replacement. While your RAID may function with a limited number of drives, it will not be fully redundant and you will face a higher chance of corruption-causing issues.
Regularly analyze your RAID and replace any hard disk drives with a relatively large number of bad sectors. Do not wait for your hard drives to fail on their own.
Finally, perform regular interval backups and full backups of all of your backups. Test your backups regularly and make sure that your business could restore from its archival backups if necessary.
Fixing Database Corruption and Recovering Your Data
If you are dealing with data loss due to database file corruption or a related issue, shut down the RAID right away. Contact a professional data recovery company that has experience with your RDBMS. Do not attempt to recover your own data unless you have a full, working backup.
Experienced data recovery engineers can work with corrupted databases using proprietary software, often providing full recoveries for their clients. At Secure Data Recovery Services, we treat physical hard drive issues in a Class 10, ISO 4 Cleanroom. Our engineers have experience with database corruption and all major RDBMS systems. Call 1-800-388-1266 to get started or for more information regarding database corruption and RAID.