The dpkg status area has become read-only, blocking package installations and updates. This usually means your filesystem encountered an error and was mounted in read-only mode for protection. Remounting it as read-write or fixing filesystem errors will resolve the issue.
When your system's filesystem detects corruption or I/O errors, it automatically switches to read-only mode to prevent further data loss. The dpkg package manager stores its status database in /var/lib/dpkg/, and when this directory becomes inaccessible due to read-only mounting, all apt and dpkg operations fail. This error typically indicates either a hardware issue, filesystem corruption, or that your filesystem was improperly unmounted. In rare cases, it may indicate disk space issues or a previous system crash that left the filesystem in an inconsistent state.
Run the mount command to see if your root filesystem is mounted as read-only:
mount | grep -E "on / |read-only"If you see "read-only" in the output, your filesystem needs to be remounted as read-write. If it shows read-write, proceed to the next step.
A full filesystem can become read-only. Check your disk usage:
df -hIf any filesystem shows 100% usage, delete unnecessary files or logs to free up space. Check /var/log for large log files that can be safely removed.
If the filesystem is mounted read-only, remount it with write access:
sudo mount -o remount,rw /After remounting, test if dpkg works:
sudo apt updateThis is a temporary fix. Reboot if you want the system to remount permanently after fixing underlying issues.
If the filesystem is writable but dpkg still fails, check for lock files:
sudo lsof /var/lib/dpkg/lock
sudo fuser -v /var/lib/dpkg/lockIf you see processes, either wait for them to complete or kill them (use with caution):
sudo killall apt apt-get dpkg
sudo rm -f /var/lib/apt/lists/lock
sudo rm -f /var/cache/apt/archives/lockThen try the operation again:
sudo dpkg --configure -a
sudo apt updateIf remounting doesn't work, you likely have filesystem corruption. Boot from a live USB/CD and run fsck:
1. Insert a live Ubuntu USB and boot from it
2. From the live environment, run:
sudo fsck /dev/sdX#Replace /dev/sdX# with your actual root partition (found via lsblk or sudo fdisk -l). This will check and repair filesystem errors.
3. After fsck completes, reboot into your normal system.
For production servers experiencing persistent read-only filesystem issues, consider these advanced troubleshooting steps:
1. Hardware Diagnostics: If fsck repairs don't persist, run hardware diagnostics:
sudo smartctl -a /dev/sdX2. SELinux or AppArmor: On systems with mandatory access controls, check if policies are blocking dpkg. Run sudo getenforce (SELinux) or check AppArmor status.
3. LVM or Encrypted Volumes: If using LVM or LUKS encryption, the issue may be at the volume level. Check sudo pvs and sudo lvs for errors.
4. Systemd Journal: For clues about filesystem errors, check:
sudo journalctl -p err --no-pager | tail -505. Mount Options: Some filesystems have additional mount options. Check /etc/fstab and ensure no options like ro (read-only) are set for your root filesystem.
If hardware diagnostics show failures or fsck cannot repair the filesystem, backup your data immediately as the drive may be failing.
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