What's the best way to protect against HDD failure?
Whatever the reason for failure, HDDs are hard to repair. Admins need to get out in front of potential issues, like the four described here, to prevent prolonged downtime.
HDDs are precision-engineered devices that contain many moving parts. Any disruption to a drive's components can cause the entire HDD to fail and result in users losing data permanently.
Even with a strong DR plan in place, IT teams should understand what causes HDDs to fail and what steps they can take to help mitigate those failures. The causes of HDD failure can generally be grouped into four broad categories: destructive external forces, internal mechanical failure, underlying logical issues and faulty firmware. These categories are not necessarily mutually exclusive. Sometimes, multiple factors are at play, but they can explain how an HDD might be at risk for failure.
Destructive external forces
HDDs are typically encased in hard metal shells that give them the appearance of solid, resilient, indestructible devices, but the reality is quite different. Inside, they are complex mechanisms with numerous moving parts whose precision is measured in nanometers. If someone mishandles a drive, the shock can wreak havoc on its internal components, whether the spindle, platters, heads or other parts.
HDDs are susceptible to environmental factors. This is particularly true with high operating temperatures, which can be caused by fan malfunctions, improper ventilation or other factors. Over time, too much heat can degrade the circuitry and erode the physical material. Natural disasters, such as earthquakes, tornadoes, floods and fires, can damage an HDD's components and cause it to fail. Too much vibration over time or an electrical disturbance can also lead to HDD failure.
A drive that's been subjected to physical abuse can exhibit an assortment of symptoms. For example, an HDD might feel hot to the touch or make clicking sounds, either of which can indicate an overheating problem. A sluggish cooling fan can also point to potential overheating. On the other hand, a system's BIOS might not be able to detect the HDD, or the drive might fail to spin up altogether, either of which can be the result of a power surge.
To protect HDDs from outside forces, IT teams should start by defining a plan that details how users should physically handle drives and what steps can minimize environmental hazards. These guidelines should outline how to maintain the proper temperature and humidity, avoid static electricity and safely store the drives. In addition, IT teams need to keep the drive's location clean, dust free and well ventilated. Power supplies, cables and uninterruptible power supplies should be in good working order.
Internal mechanical failure
HDDs commonly experience internal issues. One of the most common is a head crash, in which the read/write head touches the platter, damaging its surface, which leads to data loss. A head crash might be the result of physical trauma, a manufacturer defect or an electrical malfunction. Another common issue is stiction, which occurs when the armature that drives the flying head gets stuck, often because of prolonged disuse.
One of the most common causes of HDD failure is normal wear and tear, however. An HDD can run for only so long before its components start to degrade.
Although relatively rare, an HDD's motor might fail because of inadequate lubrication, excessive heat or other reasons. That said, problems are more likely to occur with the printed circuit board (PCB), which can malfunction for reasons such as moisture or static electricity. An HDD can also experience bad sectors, in which entire sections of the disk become unusable. An increasing number of bad sectors can lead to data loss and a failed drive.
A number of signs indicate internal issues. For instance, corrupt data or frequent boot errors might point to malware or suggest a growing number of bad sectors. Noises such as clicking, knocking or grinding denote a serious problem, whether from a head crash, malfunctioning motor or another cause. Smoke or burning smells, which could occur if an electrical surge burns out the PCB, for example, suggest a problem.
Carefully monitor HDDs for imminent failure. Start with SMART, a diagnostic tool built into most of today's enterprise drives. SMART -- which stands for self-monitoring, analysis and reporting technology -- can help administrators identify metrics that might point to imminent failure. IT should also use other monitoring tools and replace aging HDDs before they fail.
Underlying logical issues
HDD failure can stem from logical issues rooted in the software or data rather than in the physical components. For example, software bugs can corrupt or delete data, preventing the HDD from operating properly or even potentially damaging the hardware. If data such as the Master Boot Record becomes corrupted, the entire HDD might become unreadable.
One of the biggest culprits is malware, which can come in a variety of forms, including worms, viruses, Trojans, rootkits or fileless malware. Malware affects how an HDD operates or destroys the drive's file system. It also causes physical damage. For example, malware might attempt to run excessive read/write operations, manipulate a system's cooling fans or overload the power supply, any of which could lead to HDD failure.
HDDs are also susceptible to user error. For example, a storage server administrator might install buggy software, improperly alter system settings or shut down the system.
If an HDD is starting to fail because of logical problems, administrators might see increasing amounts of corrupt data or erratic error messages. They might find that some files don't open or that others have been renamed. A server freezing is another sign, depending on how the storage system is configured.
To protect against logical issues, IT should ensure all its team members are carefully trained in how to work with the organization's storage systems. For example, they should know how to shut down and disconnect systems and exercise caution when installing software.
The team should run antimalware software; regularly scan storage systems; implement security protections, such as firewalls; and properly update and patch systems. Perform regular maintenance on the storage systems, such as defragmenting the HDDs and performing regular disk scans.
Faulty firmware
Like other components, firmware is vulnerable to malware, inappropriate shutdowns and interruptions to the power supply. Manufacturing defects or issues when performing upgrades can also be the source of problems. The firmware manages the drive's basic functions, carries out maintenance operations, and facilitates communications between the drive and other components. If a problem occurs in the firmware, the HDD could become unstable or unusable.
A drive's firmware can come from a manufacturer with defects, perhaps caused by poor design, lack of quality control or a flawed manufacturing process. A manufacturer might release a drive to market without fully testing it under realistic workloads, in which case inherent flaws are not apparent until the customer puts the drive into production.
Drives that suffer from buggy firmware tend to fail soon after purchase, rather than after long-term usage. Even well-designed firmware is susceptible to many of the same factors that threaten a drive's other logical components, however.
Signs of a firmware problem can be difficult to distinguish from other potential problems. For example, flawed firmware can cause a system to freeze or fail to boot, or the drive might become undetectable. Although this behavior suggests a possible problem with the firmware, it can also point to other causes, including mechanical problems.
Admins can do little to prevent an HDD from failing if the cause is from defective firmware, unless they can replace the firmware. They can protect against malware, ensure a reliable power supply and perform firmware updates only under controlled conditions. If a drive fails and the culprit appears to be defective firmware, the team should follow up with the vendor, assuming the drive is still under warranty. They should also take the drive to a recovery lab to try to salvage important data.
Robert Sheldon is a technical consultant and freelance technology writer. He has written numerous books, articles and training materials related to Windows, databases, business intelligence and other areas of technology.