5 Reasons to Not Rely on RAID
I’ve met and spoke with quite a few persons who believe that RAID is the answer to all of their data-safety needs. There is only one thing I can say about relying solely on RAID: “It’s a horrible idea!”. RAID is a good supplemental protection mechanism in your entire data integrity plan but it is not THE answer.
- RAID is usually susceptible to double-disk RAID faults. While this may not sound like a normal or even conceivable possibility it is a very real issue that I have personally experienced. RAID-6 offers some higher levels of protection to this problem. Most new 9600 series 3Ware controllers (and most newer controllers) offer RAID-6 capabilities. Choose a RAID-6 able card and, if possible, always run a BBU (Battery Backup Unit).
- RAID will never protect against file corruption or viruses.
- RAID can’t protect against human error. We’re all human, we all make mistakes. If you just hit the delete key on an entire directory of your company’s data then you can probably hit the delete key on your job as well. This is why backups, along with RAID, is the best data integrity solution.
- RAID will only protect you if you are proactive. Some lower quality RAID controllers do not send email alerts and do not properly alert you of an issue. These controllers require special attention. The more user interaction is needed the less likely you will notice a fault. Having a hot spare or spare disks available for swapping is always a good idea.
- RAID will not facilitate off-site and disaster recovery scenarios. There are some utilities out there that provide block-level replication.
In summary, the best data integrity plan is to use RAID to supplement your plan. Don’t rely on RAID as your sole backup/data security mechanism. I personally recommend using RAID-6 with a block-level backup of all data to an off-site location. Using software like R1Soft’s CDP will allow for full block-level backups and file-level and bare-metal restores. Remember to always double check your data integrity plan and never be satisfied with your solution! I personally hate loosing data. With drives as cheap as they are today, why aren’t you backing up offsite?