Troubleshooting Hard Drives & RAID Arrays | CompTIA A+ 220-1001 | 5.3

In this video you will learn about issues associated with hard drives & RAID arrays.

Common Symptoms

Common symptoms associated with hard drives that can affect the overall performance of a hard drive are:

• Read/write failures:  Caused by dropping the magnetic drive, damaged cables (swap out cables), damaged SATA host adapter on the motherboard, overheated hard disk, & overheated CPU or chipset (remove dust/dirt, remove loose/failed heat sinks, remove old thermal grease).
• Slow performance:  Caused by reduced-performance configuration of 3Gbps or 6Gbps drives, using 3Gbps cables with 6Gbps drives & host adapters, SATA host adapters that have been configured for IDE (emulation) mode, and SATA host adapters that have been configured to run at reduced speeds
• Loud clicking noises:  Can be caused by repeated rereads of defective disk surfaces by the hard disk drive heads; make backups immediately & replace the disk.  Humming noises can be caused by rapid head movement on a normally functioning hard disk.
• Failure to boot:  Boot sequence does not specify hard disk or lists system hard disk after drives with non-bootable media.  CMOS settings have been corrupted & the system cannot find a bootable drive.  The boot configuration data store used by Windows to control disk booting has been corrupted.
• Drive not being recognized:  Bus-powered USB hard disk is not recognized, USB or Thunderbolt drive is not recognized, & SATA hard disk or SSD drive is not recognized.
• Operating system not being found:  Non-bootable disk in the USB drive, boot sequence doesn’t list hard disk, incorrect installation of another operating system.
• RAID Not Found:  
  • RAID function disabled in system BIOS:  Reconfigure SATA ports used for RAID as RAID & restart the system.
  • Power or data cables to RAID drives disconnected:  Reconnect cables to RAID drive(s) & restart the system.
• RAID Stops Working:  Failure is caused by the failure of 1 or more disk drives in the RAID array.
  • RAID 0:  Determine which drive has failed.  Replace it & follow the vendor’s recommendations to recreate the array.  Restore the latest backup.  Any data that has not been backed up will be lost.
  • RAID 1, 10, & 5:  Determine which drive has failed.  Replace it.  Follow the procedures provided by the RAID vendor to rebuild the array.
  • If both drives have failed in a RAID 0 or 1 array, the arrays must be rebuilt with new drives & the latest backup has to be restored.  Any data that has not been back up will be lost.
  • If two or more drives have failed in a RAID 10 or 5 array, recovery options may vary according to the exact configuration of the array.  For recovery options, see the RAID vendor’s documentation.
• S.M.A.R.T. Errors:  Self-Monitoring, Analysis, & Reporting Technology is a defect-warning feature supported by both SATA & PATA hard disks.  When S.M.A.R.T. errors are displayed, back up the system immediately.  To determine if the drive is actually bad or if the message was a false positive, download and run the disk testing software provided by your system or drive vendor.  Typical items that are monitored are:
  • Drive temperature
  • Read retries
  • Slow spin-up
  • Too many bad sectors
• S.M.A.R.T. Warnings:
  • Hard disk failure is imminent
  • A hard drive in your system reports that it may fail
  • Smart failure imminent, backup your data