Terminal becomes unresponsive when running grep on external SSD

Description

When Claude Code runs a grep command on an external SSD, the terminal hosting Claude Code becomes completely unresponsive/frozen rather than showing the command running in the background while remaining interactive.

Expected behavior

Claude Code should remain responsive while a long-running command executes, showing the command is running and allowing user interaction (like Ctrl+C to cancel).

Actual behavior

The entire terminal freezes and becomes unresponsive. Cannot type, scroll, or interact with the terminal at all.

Environment

• Claude Code version: 2.1.15
• OS: Linux 6.17.0-19-generic (Ubuntu)
• Platform: x86_64
• Memory: 20GB total

Diagnostic findings

When the issue occurred:

• One Claude session was consuming 2.4GB RSS memory (unusually high)
• External SSD showed read bursts of 73MB/s
• I/O wait spiked from 0.17% to 2.85%
• Process had 21 threads in "Running" state
• The session was accessing files on the external SSD mount (/mnt/ssk-ssd/)

Hypothesis

The freeze appears to be caused by one of:

1. Massive grep output overwhelming terminal buffer
2. Node.js event loop blocked during I/O operations on slow external storage
3. Memory pressure from buffering large command output

Steps to reproduce

1. Start Claude Code in a terminal
2. Have Claude run a grep command across a large directory on an external SSD
3. Observe terminal becomes frozen/unresponsive

Workaround

Kill the process from another terminal:

pkill -f "grep.*<pattern>"
# or
kill <claude-pid>

Additional context

• The frozen session was working with project files on /mnt/ssk-ssd/tony/GitHub/KinDash/
• Normal behavior would be Claude showing the command running while remaining responsive