5.3 - Troubleshooting Storage Devices Flashcards
Storage failure symptoms
Read/write failure
– “Cannot read from the source disk”
Slow performance
– Constant LED activity - Retry…retry…retry
Loud clicking noise
– The click of death
– May also include grinding and scraping
Troubleshooting disk failures
Get a backup - First thing - a bad drive is bad
Check for loose or damaged cables
Check for overheating
– Especially if problems occur after startup
Check power supply
– Especially if new devices were added
Run hard drive diagnostics
– From the drive or computer manufacturer
– Preferably on a known-good computer
Boot failure symptoms
Drive not recognized, Boot Device Not Found
– Lights (or no lights)
– Beeps
– Error messages
Operating system not found
– The drive is there
– Windows is not
Troubleshooting boot failures
Check your cables
– Physical problem
Check boot sequence in BIOS
– Check for removable disks (especially USB)
– Check for disabled storage interfaces
For new installation, check hardware configuration
– Data and power cables
– Try different SATA interfaces
Try the drive in a different computer
Data loss/corruption
Hard drives are mechanical devices
– They will eventually fail
Repairs are difficult and expensive
– Dust-free environment
– Not always successful
An SSD may simply stop working
– Sometimes can read but not write
Data becomes unavailable or corrupted
– Can be impossible to recover
ALWAYS HAVE A BACKUP
RAID not found
Missing or faulty RAID controller
RAID stops working
Each RAID is different
– Don’t start pulling drives until you check the console!
S.M.A.R.T.
Self-Monitoring, Analysis, and Reporting Technology
– Use third-party utilities
Avoid hardware failure - Look for warning signs
Schedule disk checks - Built-in to most drive arrays
Warning signs - Replace a drive
Extended read/write times
A lot happens when reading or writing data
– Memory access, communication across the bus,
spinning drive access, writing or reading the data to
the storage device, etc.
Delays can occur anywhere along the way
– Need a way to measure storage device access
Input/output operations per second (IOPS)
– A broad metric of maximum performance
Useful for comparing storage devices
– Hard drive: 200 IOPS
– SSD: 1,000,000 IOPS
Missing drives in OS
OS boots normally
– Other drives not shown - Check the BIOS
Internal drives
– Bad drive or disconnected cable
External drives
– No power to the drive or bad cable connection
Network shares
– Shared drives can be connected during startup
– Option to reconnect at sign-in
– Connected with login script
