5.3 Troubleshooting Storage Devices and Raid Arrays

Question 1

LED Status Indicators

Answer 1

LED activity shows the status of the hard drive
- flashing LED usually means that the drive is reading or writing data
- flashing LED when there is no activity can be a sign of a failing hard drive or faulty connection
- no lights can also be a sign of hard drive issues

Question 2

Grinding and Clicking Noises

Answer 2

sign of a failing or already failed hard drive

Question 3

Bootable Device Not Found

Answer 3

Check cable connections

Check boot sequence in BIOS:
- removable disks such as USBs can cause boot issues
- check for disabled storage devices

When booting from a new storage device, check the hardware config

Try the drive on a different computer

Question 4

Data Loss/Corruption

Answer 4

• hard drives will eventually fail due to moving parts
• repairing and recovering data from a hard drive can be very difficult and expensive
• SSD can also fail: sometimes can read but not write
• can be impossible to recover
• ALWAYS HAVE A BACKUP

Question 5

RAID Failure

Answer 5

• check storage/RAID manager to see what happened
• each RAID is different, check the console!

Question 6

Self-monitoring, Analysis, and Reporting Technology (SMART) Failure

Answer 6

• utilities/software from the drive manufacturer or a third party
• monitor storage devices
• look for warning signs to avoid hardware failure
• schedule disk checks

Question 7

Extended read/write times

Answer 7

• a lot happens when reading or writing data
• delays can occur anywhere along the way

Question 8

Input/Output operations per second (IOPS)

Answer 8

• a broad metric of maximum performance

Question 9

Missing drives in OS

Answer 9

• when OS boots normally but other drives are not shown
• Internal drives: can be a bad drive or faulty/disconnected cable
• External drives: no power to the drive or faulty cable connection
• Network share: reconnect to network share or connect with login script