Anthropic Cowork feature creates 10GB VM bundle on macOS without warning

Original Article ↗ Hacker News Discussion ↗

Anthropic’s Claude Cowork feature on macOS quietly creates a ~10 GB virtual machine bundle to sandbox its coding agent, which many users only discover when they run out of disk space or hit nested-VM errors. Commenters debate whether a full VM is justified for safety and non-technical user protection versus lighter sandboxing approaches, while criticizing the lack of transparency, performance and power impacts, and broader trends of apps consuming opaque “System Data” storage. Some praise Cowork’s productivity benefits but argue that tools using substantial local resources should clearly disclose their behavior and offer more control over storage, placement, and security trade-offs.

VM-based Cowork design & rationale

  • Claude Cowork on macOS/Windows runs inside a Linux VM via Apple’s Virtualization framework or Microsoft’s Host Compute System.
  • Stated goals:
    • Give the model its “own computer” to freely install tools and run scripts without touching the host.
    • Strong isolation guarantees versus lighter sandboxing (containers, seatbelt, etc.).
    • Reduce risk for non-technical users who can’t safely vet arbitrary commands and suffer from “approval fatigue.”
  • Some commenters see this as the right tradeoff for “agents” and regulated environments; others argue containers or alternate sandboxes could suffice.

Storage, performance, and UX complaints

  • Cowork creates a ~10 GB VM bundle on macOS (and similar on Windows) without an explicit warning.
  • Users report:
    • Surprise at the disk usage, especially on small SSDs or metered connections.
    • The VM image starting mostly full, leaving little room for tasks; it can fill up and break Cowork.
    • VM RAM usage and power draw even when Cowork is disabled.
  • Some workarounds: delete or resize the VM bundle, move/symlink to other disks, or avoid the desktop app and use the web.
  • Many want:
    • A clear prompt before downloading/creating the VM.
    • A one-click way to remove or relocate it.
    • Options to disable Cowork, use a lighter sandbox, or restrict host filesystem access to chosen folders.

Broader macOS disk-usage frustration

  • Thread broadens into complaints about opaque “System Data” and aggressive caching (Docker/Podman VMs, Time Machine snapshots, Podcasts, Messages, Photos).
  • Tools like ncdu, GrandPerspective, DaisyDisk, and others are recommended to find large, hidden directories.
  • Some note SIP and permissions make it hard to even see or delete certain files and snapshots.

Quality, development practices, and “vibe coding”

  • Several users praise the models and Claude Code CLI, but describe desktop apps/Cowork as buggy, resource-heavy, and shipped “too fast.”
  • Concerns that parts of the product and even GitHub issues themselves are “vibe coded” or AI-generated, leading to misleading bug reports.
  • Others counter that VM isolation and fast iteration are acceptable tradeoffs, especially for non-expert users and SMBs, but call for better diagnostics (“doctor” tools) and error messaging.