Claude Code storage incident

Claude Code Windows ENOSPC Write Error

If Claude Code on Windows logs ENOSPC: no space left on device, write, do not start by deleting session history or project files. First prove which filesystem is full: the Windows profile drive, Bun root, temp folder, Claude state, or a mounted workspace path such as B:\~BUN.

Read-Only Evidence

Claude Code can surface storage errors from several places on Windows. The fastest safe triage is to measure each likely location without printing file contents.

Get-PSDrive -PSProvider FileSystem | Sort-Object Free | Format-Table Name,Root,Used,Free

$paths = @(
  $env:TEMP,
  $env:TMP,
  "$env:USERPROFILE\.claude",
  "$env:APPDATA\Claude",
  "$env:LOCALAPPDATA\Claude",
  "B:\~BUN"
) | Select-Object -Unique

foreach ($path in $paths) {
  if (Test-Path -LiteralPath $path) {
    $stats = Get-ChildItem -LiteralPath $path -Force -Recurse -ErrorAction SilentlyContinue |
      Measure-Object -Property Length -Sum
    [pscustomobject]@{
      Path = $path
      Files = $stats.Count
      GB = [math]::Round(($stats.Sum / 1GB), 2)
    }
  }
}

Get-ChildItem -LiteralPath $env:TEMP -Force -Recurse -ErrorAction SilentlyContinue |
  Sort-Object Length -Descending |
  Select-Object -First 40 FullName,@{Name='MB';Expression={[math]::Round($_.Length/1MB,1)}},LastWriteTime

What The Output Means

1. Profile drive full: Downloads, caches, package stores, and app data may be the real blocker before Claude state is involved.
2. Temp folder full: stale installers, extracted bundles, crash dumps, or agent scratch files can block new writes.
3. Claude state large: session history, logs, and tool output need review before deletion because they may be the only recovery trail.
4. Bun root or mounted drive full: the failing path can be outside C:, so drive-level checks must include the path shown in the error.

Do Not Delete First

• Do not delete active Claude session directories, transcripts, or project state until you know whether recovery is needed.
• Do not clear every temp folder while Claude or build tools are still running.
• Do not remove package caches that your current project needs until you know whether they are rebuildable.
• Do not paste secrets, private file contents, or full transcripts into a public issue.