The Truth About RAID and Data Corruption

The Truth About RAID and Data Corruption

January 15

If you’ve been following the StorageCraft journey on RAID, you may view this disk mirroring concept as a rock-solid solution for systems that demand the highest availability. And it is, to a degree. Be it a hardware or software implementation, you can count on RAID to minimize the sting of single disk failure and promote better overall performance. But RAID is far from perfect, and its flaws are highlighted when data corruption comes into play.

The goal of RAID, particularly level 1, is creating two equal disks so if one fails physically, your data is still available on the other. Unfortunately, RAID is incapable of determining which of the two disks is bad. Therefore, if no failure is detected, the system assumes everything is accurate and data from the corrupted drive is automatically copied to second drive. This goes back to a previous post where we discussed how RAID enables problems to propagate faster and essentially doubles your trouble.

Corruption is a serious threat to data in any IT environment. It has several root causes, including:

  • Improper system shutdownS
  • System crashes or freezes
  • Sudden power outages
  • Hard drive failures, bad disk sectors, and other hardware-related problems
  • Failure to eject hard drives and storage devices before properly turning them off or disconnecting them
  • Virus infections

Keeping It Real With RAID

The good thing about RAID is that it comes in many formats, and generally becomes more reliable the higher you go up in levels. For example, RAID 5 is known to provide better performance and hot-swapping capabilities that let you switch out failed arrays in servers and NAS devices without shutting down the system. RAID 6 offers added reliability with a double parity architecture that allows disks to fail not once, but twice before you have to worry about data loss. But no matter how high you climb, RAID at any level is not an ideal solution for data corruption.

If you’re intent on using RAID, there are a few strategies you can implement to safeguard your systems against the ever looming threat of data corruption.

Enforce proper shutdowns and disconnections: Make sure all users understand the importance of properly shutting down the system and disconnecting external storage devices. Ignoring this rule can lead to data corruption and leave you scrambling to recover data on a drive that is no longer accessible.

Invest in UPS: Power outages, surges, and brownouts can corrupt your data and damage your hardware as well. Consider using an Uninterruptible Power Supply or UPS, system that provides backup power when the main electrical source fails.

Address issues as they arise: Forcing your system to shutdown with a hard restart won’t magically make your problems disappear. Put your troubleshooting hat on to determine what led to those problems or you could compound them with corrupted data and a host of other issues.

Practice safe surfing: The web is a dangerous place. Be cautious of browsing malicious websites or downloading software that can corrupt your data and unleash havoc on your systems.

Plan for BDR: A backup and recovery strategy is the only true way to protect your data from hard drive failure and other events that cause corruption. Without it, you greatly increase the risk of losing your mission critical data sooner rather than later.

RAID Recovery to the Rescue

In the event that you’re just plain unlucky and still end up with a corrupted data dilemma, don’t panic just yet. You may be able to repair those damaged disks by using a special recovery tool. RAID recovery software works by reconstructing broken arrays in hardware, software, and native configurations. This software is available in both free and commercial versions for every major operating system. Do your homework to find a tool most likely to deliver on the promise resurrecting your wounded data from death’s doorstep.

Photo Credit: Alper Cugun via Flickr