5.3 Given a scenario, troubleshoot and diagnose problems with storage drives and RAID arrays.
- Common Symptoms
- Light-Emitting Diode (LED) Status Indicators
- Grinding Noises
- Clicking Sounds
- Bootable Device Not Found
- Data Loss / Corruption
- RAID Failure
- Self-Monitoring, Analysis and Reporting Technology (SMART) Failure
- Extended Read/Write Times
- Input / Output Operations Per Second (IOPS)
- Missing Drives in OS
Hard Drive Issues
When diagnosing a hard drive issue
- Determine whether you have a magnetic drive or a solid-state drive. They function differently.
- Be proactive about backing up your data. Most hard drive issues are physical in nature and can’t be corrected. The easiest solution is to replace the drive. If you have a back up, then you don’t have to worry. As the condition of the drive deteriorates, data recovery becomes less and less likely. Solid state drives fail catastrophically and sometimes no recovery is possible.
|Can be caused by a software bug, especially if multiple users/hard disk drives are affected.
Can be caused by damage to the hard disk drive.
Extended Read/Write Times
Input / Output Operations Per Second (IOPS)
|Disk is fragmented. Run disk defragmenter.
Disk is functioning well, but computer is slow. Computer may require more memory or a faster processor.
Replace the SATA cable.
We measure the performance of a hard disk drive in IOPS, or Input / Output Operations Per Second
|Grinding Noise or Loud Clicking Noise
|Mechanical problem with the hard disk drive. Replace the drive.
|Failure to Boot
|Check the boot order in the BIOS, and make sure that the HDD is set to boot. Make sure that the HDD is connected to the SATA and power cables.
The HDD circuitry may have a fuse that burned out Run check disk utility to correct any data errors Operating system is corrupted. Reinstall the operating system
|Drive Not Recognized
|A drive with the wrong file system is connected (for example HFS+ drive connected to a Windows computer)
Check to see that the SATA cable is connected securely
Check to see that the power cable is connected properly, and that the PSU is outputting adequate power
Check that the drive is enabled in the BIOS Check that you have installed the correct drivers for the HDD
|OS Not Found
|Check that you are booting in the correct mode (legacy or UFEI). Check if there are errors with the operating system. Insert a bootable operating system DVD/USB and attempt to correct errors
|Check the cause of the error and act as appropriate
|SMART = Self-Monitoring, Analysis, and Reporting Technology
SMART monitors the drive for errors and predicts hardware failures. SMART warns you prior to the failure of the HDD
When seeing a SMART warning, back up data and replace the HDD
|LED Status Indicators
|Server hard disk drives have LEDs
A green LED indicates that the drive is healthy
A red or orange (amber) LED usually indicates that the drive is about to fail or has failed
|Data Loss / Corruption
|The drive is failing. It may be suffering a mechanical failure or a circuitry failure.
Replace the drive.
|Missing Drives in OS
|When we have multiple drives in our computer, one of them may not show up
Verify that the drive is connected to the power and SATA cables
Verify that the driver is installed
Verify that the drive is formatted
|RAID Not Found
|The BIOS might be ignoring the RAID controller. Check the BIOS to see if RAID is enabled, or if the computer is set to boot from AHCI. If the problem is with the RAID setup, then the possible issues are
-Too many RAID disks have failed, rendering the entire array defective
-The RAID volume itself was deleted
-The RAID controller is defective
Log in to the RAID controller (normally it’s possible to access the RAID controller through an option such as CTRL+J, which is accessible when the computer is booting). If you can’t reach the RAID controller, it may have failed.
-Try reseating the RAID controller, or controller cables. Replace the controller if appears to be failing.
-If it’s an integrated controller, the system board may have to be replaced.
Log in to the controller to see if the virtual disks are present. If the virtual disk configuration is lost, but the physical disks are still functional, you can try to have the controller “detect” the original configuration. Check inside the controller to see if the disks are functional. The disks may not be seated correctly.
The disks sit inside a backplane, and the backplane may be loose. Try to reseat the backplane.
|RAID Stops Working
|One or more disks have failed
Typically, an enterprise disk will show an error light on the front (a red or amber light) indicating that it has failed. If you’re using RAID 5, or another redundant RAID version, the failure of a single disk won’t cause data loss. But you must replace the disk. The failure of an additional disk could result in complete data loss.