Kai Mallari's Notes'

EC - External SSD Failure

3 min read

External SSD Failure

Symptom: External SSD disconnects during the shoot, transfers fail, or the SSD becomes very slow after extended use. Root Cause: Physical disconnection (cable snagged), NVMe thermal throttling, or SSD firmware crash. Referred from: DIT Triage - Slow Performance, DIT Triage - Tether Drops

Diagnosis

1. Did the SSD physically disconnect?

  • The cable was bumped, snagged by crew, or pulled.
  • Finder will show a “Disk Not Ejected Properly” warning.
  • If this happened during a write (capture or file copy), the last file may be corrupt.
  • Fix: Reconnect the SSD. Check the last file written. If corrupt, delete it. Resume shooting.

2. Is the SSD thermal throttling?

  • NVMe SSDs in enclosed cases (Samsung T7, SanDisk Extreme Pro, etc.) generate significant heat during sustained writes. The SSD firmware throttles write speed when the internal temperature exceeds safe limits.
  • Symptoms: Transfer speeds that start fast (500+ MB/s) and progressively decrease to 50-100 MB/s after 20-30 minutes of continuous captures.
  • Check: Feel the SSD enclosure. If it’s very hot to the touch (uncomfortable to hold), it’s thermal throttling.
  • Fix: Take a 5-minute break to let it cool. If possible, remove the SSD from its case or prop it up for airflow. Point a fan at it.
  • For sustained high-throughput shoots: switch capture destination to internal NVMe storage (much better thermal management). Copy to the external SSD during breaks.

3. Did the SSD firmware crash?

  • Rare but possible. The SSD becomes unresponsive — Finder shows it as “not mounted” or it disappears from Disk Utility entirely.
  • Fix: Disconnect the SSD. Wait 30 seconds. Reconnect. If it still doesn’t mount: try a different cable, then a different port. If still unresponsive: power cycle (disconnect for 60 seconds).
  • If the SSD doesn’t recover: the session data on that SSD may be lost. Switch capture destination to internal storage or another drive immediately. Data recovery from the SSD can be attempted later.

Fix

ProblemFix
Physical disconnectReconnect, check last file, resume
Thermal throttleCool down, switch to internal storage, resume
Firmware crashDisconnect 60s, reconnect, if dead switch drives

Prevention

  • Secure the SSD cable. Gaffer tape the cable to the table at both the SSD end and the laptop end. Leave slack for movement.
  • Avoid enclosed cases for long shoots. If possible, use an NVMe SSD in an open heatsink enclosure rather than a sealed enclosure.
  • Use internal storage as primary capture destination on high-volume shoots. Copy to external SSD during breaks.
  • Test the SSD before the shoot. Copy a large folder (10+ GB) to the SSD to confirm sustained write speeds are acceptable.
  • Carry a spare SSD and cable in the DIT kit.

Documentation

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