hdparm

Get/set disk parameters

high risk

interactive breakdown — edit the command and press Explain
$ 
⚠ Risks & cautions
Safer / dry-run alternatives
hdparm -I <device>Identify before changing anything
What it does

Queries disk info and benchmarks; can change power, cache and security features.

Common flags
FlagMeaning
-IIdentify device
-tBenchmark reads
--security-erase --security-eraseSecure erase⚠ Destroys all data.
Examples
hdparm -I /dev/sdaDrive info · explain & risk-check →
hdparm -t /dev/sdaRead speed test · explain & risk-check →
Related
smartctl lsblk
Open the full explainer →More in Disks & Filesystems

Reference text is hand-written and may be incomplete — check man hdparm for your version. Test destructive commands on a non-production system first.