Linux Read-Only File System

Overview

Linux "Read-only file system" (EROFS) means the filesystem has been mounted read-only or remounted read-only due to errors.

Key Details

• errno 30 — EROFS, cannot write to the filesystem
• Filesystem may have been remounted RO due to errors
• Common after kernel detects filesystem corruption
• Snap/Flatpak containers have read-only rootfs

Common Causes

• Filesystem corruption detected — kernel remounted RO
• fstab entry specifying read-only mount
• Hardware write-protect switch on USB/SD card
• Container or snap filesystem isolation

Steps

1. 1Check mount options: mount | grep /dev/sdX
2. 2Remount read-write: sudo mount -o remount,rw /
3. 3If corruption: unmount and run fsck
4. 4Check dmesg for filesystem error messages

Tags

More in Filesystem

Frequently Asked Questions