How to fix fatal: Unable to create lock file: No locks available (NFS filesystem) in Git

What this error means

The "Unable to create lock file: No locks available" error on NFS filesystems indicates that Git's file locking mechanism is failing at the operating system level. Git relies heavily on lock files to prevent concurrent modifications and ensure data integrity, but NFS (Network File System) handles file locking differently than local filesystems. NFS uses a separate lock manager (lockd/statd on Linux) to coordinate file locks across networked clients. When this error occurs, it means one of the following: - **The NFS lock daemon (rpc.lockd/rpc.statd) is not running** on the client or server - **The NFS mount was created with the `nolock` option**, explicitly disabling locking - **The NFS server does not support or has disabled locking** - **A firewall is blocking the NFS lock ports** (typically UDP/TCP 32803 and 32769) The underlying system call returns ENOLCK (No locks available), which Git surfaces as this fatal error. Unlike the "index.lock exists" error where a stale lock file is the problem, this error means the system cannot create locks at all. This is particularly common when: - Working with Git repositories on NAS devices or networked storage - Using NFS home directories in enterprise or academic environments - Running containerized builds with NFS-mounted volumes - Working in cloud environments with shared file storage

Typical symptoms

• Git commands fail with 'fatal: Unable to create lock file: No locks available'
• The error specifically mentions NFS filesystem or appears only on network-mounted directories
• Git works fine on local directories but fails on NFS-mounted paths
• The error appears for any Git operation that requires locking (commit, checkout, pull, etc.)
• Multiple users or machines accessing the same NFS-mounted repository experience the issue
• The error started after mounting a new NFS share or changing mount options
• Docker containers or CI/CD jobs fail when using NFS-mounted Git repositories

Common causes

1. The NFS mount was created with the 'nolock' option, disabling file locking entirely
2. The NFS lock daemon (rpc.lockd/rpc.statd) is not running on the client system
3. The NFS server does not support or has disabled the NFS lock manager
4. A firewall is blocking NFS lock manager ports between client and server
5. The NFS server is NFSv4 but the lock service is not properly configured
6. The NFS mount uses an older protocol version that doesn't support locking properly
7. SELinux or AppArmor policies are blocking lock file creation
8. The NFS export options on the server restrict locking operations

How to fix "fatal: Unable to create lock file: No locks available (NFS filesystem)"

# Check mount options for all NFS mounts
mount | grep nfs

# Or check a specific mount point
mount | grep /path/to/your/repo

# Look for 'nolock' in the output - if present, locking is disabled
# Example output with locking disabled:
# server:/export on /mnt/nfs type nfs (rw,nolock,addr=192.168.1.100)

cat /proc/mounts | grep nfs

# Unmount the NFS share (ensure no processes are using it)
sudo umount /mnt/nfs

# Remount with locking enabled (remove nolock option)
sudo mount -t nfs -o rw,hard,intr server:/export /mnt/nfs

# Or if using NFSv4:
sudo mount -t nfs4 -o rw,hard,intr server:/export /mnt/nfs

# Before (locking disabled):
server:/export  /mnt/nfs  nfs  rw,nolock  0  0

# After (locking enabled - remove nolock):
server:/export  /mnt/nfs  nfs  rw,hard,intr  0  0

sudo mount -o remount /mnt/nfs

# Check status of NFS client services
sudo systemctl status nfs-client.target
sudo systemctl status rpc-statd

# Start and enable the services
sudo systemctl enable rpc-statd
sudo systemctl start rpc-statd

# For some distributions, you may also need:
sudo systemctl enable nfs-lock
sudo systemctl start nfs-lock

# Restart NFS client services to apply
sudo systemctl restart nfs-utils

# Check if services are running
service nfslock status
service rpcbind status

# Start the services
sudo service rpcbind start
sudo service nfslock start

# Enable at boot
sudo chkconfig rpcbind on
sudo chkconfig nfslock on

rpcinfo -p | grep -E 'nlockmgr|status'
# You should see entries for nlockmgr (lockd) and status (statd)

# Check current firewall rules
sudo firewall-cmd --list-all

# Add NFS and related services
sudo firewall-cmd --permanent --add-service=nfs
sudo firewall-cmd --permanent --add-service=rpc-bind
sudo firewall-cmd --permanent --add-service=mountd

# Reload firewall
sudo firewall-cmd --reload

# Allow NFS-related traffic
sudo iptables -A INPUT -p tcp --dport 111 -j ACCEPT
sudo iptables -A INPUT -p udp --dport 111 -j ACCEPT
sudo iptables -A INPUT -p tcp --dport 2049 -j ACCEPT
sudo iptables -A INPUT -p udp --dport 2049 -j ACCEPT

# Mount using NFSv4 explicitly
sudo mount -t nfs4 server:/export /mnt/nfs

# Or specify version in mount options
sudo mount -t nfs -o vers=4,rw,hard,intr server:/export /mnt/nfs

server:/export  /mnt/nfs  nfs4  rw,hard,intr  0  0

nfsstat -m
# Look for "vers=4" in the output

# On the NFS server
cat /proc/fs/nfsd/versions
# Should show +4 or +4.1 for NFSv4 support

# Clone to local filesystem
git clone https://github.com/user/repo.git ~/local-repo

# Work locally, then sync to NFS for backup/sharing
rsync -av --exclude='.git' ~/local-repo/ /mnt/nfs/repo/

# Keep the .git directory on local storage
mkdir -p ~/git-storage/myrepo.git
git clone --bare https://github.com/user/repo.git ~/git-storage/myrepo.git

# Create a worktree on NFS for the files
git -C ~/git-storage/myrepo.git worktree add /mnt/nfs/myrepo main

# Move .git to local storage
mv /mnt/nfs/repo/.git ~/local-git-storage/repo.git

# Create symlink
ln -s ~/local-git-storage/repo.git /mnt/nfs/repo/.git

# Set index to local filesystem
export GIT_INDEX_FILE=/tmp/git-index-$(basename $(pwd))

# Now run Git commands
git status
git add .
git commit -m "message"

#!/bin/bash
# Save as ~/bin/nfs-git

# Generate unique index path based on repo location
REPO_HASH=$(echo "$PWD" | md5sum | cut -d' ' -f1)
export GIT_INDEX_FILE="/tmp/git-index-$REPO_HASH"

# Run git with all passed arguments
git "$@"

cat /etc/exports
# Example entry:
# /export  192.168.1.0/24(rw,sync,no_subtree_check)

sudo exportfs -ra
sudo systemctl restart nfs-server

sudo systemctl status nfs-server
sudo systemctl status rpc-statd

# Verify lock manager is registered
rpcinfo -p | grep nlockmgr

Advanced notes

# Reduce operations that need locks
git config core.preloadindex false
git config gc.auto 0  # Disable auto garbage collection

# Increase timeouts
git config http.lowSpeedLimit 0
git config http.lowSpeedTime 999999

# Docker Compose example with NFS
volumes:
  nfs_volume:
    driver: local
    driver_opts:
      type: nfs
      o: addr=server,rw,hard,intr,nfsvers=4
      device: ":/export"

# Check NFS statistics
nfsstat -c  # Client statistics
nfsstat -s  # Server statistics (on server)

# Monitor lock operations
rpcdebug -m nlm  # Enable NLM debugging (requires root)
dmesg | grep -i nfs  # Check kernel messages

# Test lock functionality
perl -e 'use Fcntl qw(:flock); open(F,">","/mnt/nfs/test.lock") or die; flock(F,LOCK_EX) or die "lock failed: $!"; print "locked"; sleep 30;'

Frequently asked questions

What does "ENOLCK" mean?

The "Unable to create lock file: No locks available" error on NFS filesystems indicates that Git's file locking mechanism is failing at the operating system level. Git relies heavily on lock files to prevent concurrent modifications and ensure data integrity, but NFS (Network File System) handles file locking differently than local filesystems. NFS uses a separate lock manager (lockd/statd on Linux) to coordinate file locks across networked clients.

How do I fix "ENOLCK"?

This error occurs when Git cannot create lock files on an NFS-mounted filesystem because NFS file locking is disabled, misconfigured, or the lock daemon is not running. The fix involves either enabling NFS locking, using a local filesystem for the repository, or configuring Git to work around the limitation.

What causes "ENOLCK"?

The NFS mount was created with the 'nolock' option, disabling file locking entirely The NFS lock daemon (rpc.lockd/rpc.statd) is not running on the client system The NFS server does not support or has disabled the NFS lock manager

Is the "ENOLCK" error serious?

It is a medium-severity error — more of a blocker than a risk. The steps above resolve it.

Related errors

• fatal: cannot create pack: Too many open files

  How to fix 'cannot create pack: Too many open files' in Git

  MEDIUM

• Error: ENOSPC: System limit for number of file watchers reached

  How to fix 'ENOSPC: System limit for number of file watchers reached' in Git

  MEDIUM

• fatal: unable to access '/path/to/repo/.git/config': Permission denied

  How to fix "unable to access .git/config: Permission denied" in Git

  MEDIUM

• error: unable to access files outside of sandbox (flatpak)

  How to fix 'unable to access files outside of sandbox' in Git (Flatpak)

  MEDIUM

• API rate limit exceeded

  How to fix 'API rate limit exceeded' in GitHub

  MEDIUM

• fatal: destination path already exists and is not an empty directory

  Destination Path Already Exists and Is Not Empty

  LOW

Official resources & further reading

• 📚Git Official Documentation
• 📖
  Git Configuration - git-scm.com(Official Docs)
• 📖
  nfs(5) - Linux man page(Official Docs)
• 💬
  Git unable to create lock - Stack Overflow(Stack Overflow)
• 💬
  NFS mount options for file locking - Server Fault(Stack Overflow)
• 📖
  NFS Configuration - Red Hat Documentation(Official Docs)