Cygwin installs packages with dependencies by default, often including documentation and rarely-used binaries. The /usr/share/doc directory alone can consume 300MB+.

For development work, this core set covers 90% of use cases:

bash coreutils curl diffutils findutils gawk git grep gzip less make patch rsync sed tar unzip vim wget zip

During installation or updates:

1. Run setup-x86_64.exe -q (or x86 for 32-bit)
2. Select "Install from Internet"
3. Change View to "Category"
4. Manually expand only needed categories

Safe-to-remove directories:

rm -rf /usr/share/doc/*
rm -rf /usr/share/man/*
find /usr/share/locale -mindepth 1 -maxdepth 1 ! -name 'en*' -exec rm -rf {} +

Edit /etc/fstab to prevent unnecessary mounts:

none /cygdrive cygdrive binary,posix=0,noacl,user 0 0

List installed packages sorted by size:

cygcheck -cd | sort -k2 -nr | head -20

To remove unneeded packages:

setup-x86_64.exe -q -P -^package1,package2,package3

For rarely-used tools, consider symlinks to a central repository:

ln -s /central_repo/bin/rare_tool /usr/local/bin/rare_tool

Create a cleanup script (~/.clean_cygwin):

#!/bin/bash
# Remove old package cache
find /setup -name "*.tar.xz" -mtime +30 -delete

# Clear temp files
rm -rf /tmp/*

# Optional: compact package database
sqlite3 /etc/setup/installed.db "VACUUM;"

Cygwin installs with many default packages, some of which may be unnecessary for your workflow. The primary space consumers are:

• /usr/lib - Contains shared libraries (often duplicated across packages)
• /usr/share - Documentation and locale data
• /var/cache - Package download cache

For most development work, these core packages provide maximum utility with minimal footprint:

bash coreutils curl diffutils findutils gawk grep gzip less make patch sed tar unzip vim wget

Add these if you need version control:

git mercurial

To reduce your current Cygwin installation size:

# Remove documentation and locale data
rm -rf /usr/share/doc/*
rm -rf /usr/share/man/*
rm -rf /usr/share/locale/*

# Clear package cache
rm -rf /var/cache/setup/*

# Remove unused compilers and dev tools (if not needed)
cygwin-delete gcc-g++ gcc-core binutils

For new installations, use the --no-admin flag and select packages manually:

setup-x86_64.exe --no-admin --packages=bash,coreutils,curl,git

Create a cleanup script to run periodically:

#!/bin/bash
# Cygwin cleanup script
echo "Cleaning temporary files..."
rm -rf /tmp/*

echo "Clearing package cache..."
rm -rf /var/cache/setup/*

echo "Removing old documentation..."
find /usr/share/doc -type f -delete

echo "Cleanup complete."

If you're on Windows 10/11 and don't specifically need Cygwin, consider WSL which has better disk management:

wsl --install -d Ubuntu
wsl --set-version Ubuntu 2