WSL 出现Read-only file system 问题修复
使用WSL时突然出现Read-only file system，仔细一看进入时有提示：
An error occurred mounting the distribution disk, it was mounted read-only as a fallback. See recovery instructions on: https://aka.ms/wsldiskmountrecovery /etc/update-motd.d/90-updates-available: line 7: /usr/share/update-notifier/notify-updates-outdated: No such file or directory run-parts: /etc/update-motd.d/90-updates-available exited with return code 127 ERROR: could not generate new MOTD This message is shown once a day. To disable it please create the /root/.hushlogin file. touch: cannot touch '/root/.motd_shown': Read-only file system -bash: export: `Files/Docker/Docker/resources/bin:/mnt/c/Program': not a valid identifier -bash: export: `Files/usbipd-win/:/mnt/c/Users/whshi/AppData/Local/Microsoft/WindowsApps:/mnt/d/Microsoft': not a valid identifier -bash: export: `Code/bin:/mnt/c/Users/whshi/AppData/Local/OpenHarmony/Sdk/9/toolchains:/snap/bin': not a valid identifier
这时整个linux系统文件都是只读挂载的，在home下创建文件或修改文件会出现Read-only file system错误提示。
root@LAPTOP-U9BLNV2M:/home# touch a touch: cannot touch 'a': Read-only file system
在windows文件浏览器下创建新文件会提示：错误0X8000FFF：灾难性故障
网上大部分修复方法是：e2fsck -f /dev/sdc，但是使用时出现报错：
/dev/sdc is mounted. e2fsck: Cannot continue, aborting.
如果出现报错可以退出wsl; wsl –shutdown
然后在powershell里执行
PS C:\Users\whshi> wsl --mount e:\WSL\ext4.vhdx --vhd --bare 操作成功完成。 PS C:\Users\whshi> wsl --list 适用于 Linux 的 Windows 子系统分发: UBUNTU-20.04-NEW (默认) Ubuntu-20.04 ubuntu-office PS C:\Users\whshi> wsl -d UBUNTU-20.04-NEW -u root e2fsck -f /dev/sdc 无法将磁盘“E:\WSL\ext4.vhdx”附加到 WSL2： 另一个程序正在使用此文件，进程无法访问。 错误代码: Wsl/Service/CreateInstance/MountVhd/HCS/ERROR_SHARING_VIOLATION PS C:\Users\whshi> wsl --system -u root e2fsck -f /dev/sdc 无法将磁盘“E:\WSL\ext4.vhdx”附加到 WSL2： 另一个程序正在使用此文件，进程无法访问。 错误代码: Wsl/Service/CreateInstance/MountVhd/HCS/ERROR_SHARING_VIOLATION PS C:\Users\whshi> wsl --shutdown PS C:\Users\whshi> wsl -d UBUNTU-20.04-NEW -u root e2fsck -f /dev/sdc e2fsck 1.45.5 (07-Jan-2020) /dev/sdc is mounted. e2fsck: Cannot continue, aborting. PS C:\Users\whshi> wsl -d UBUNTU-20.04-NEW -u root e2fsck -f /dev/sdc -y e2fsck 1.45.5 (07-Jan-2020) /dev/sdc is mounted. e2fsck: Cannot continue, aborting. PS C:\Users\whshi> wsl -d UBUNTU-20.04-NEW -u root e2fsck -f /dev/sdc -p /dev/sdc is mounted. e2fsck: Cannot continue, aborting. PS C:\Users\whshi> wsl --system -u root e2fsck -f /dev/sdc e2fsck 1.46.5 (30-Dec-2021) Warning! /dev/sdc is mounted. /dev/sdc: recovering journal Pass 1: Checking inodes, blocks, and sizes Pass 2: Checking directory structure Pass 3: Checking directory connectivity Pass 4: Checking reference counts Pass 5: Checking group summary information Block bitmap differences: +(145588012--145588014) -(145682212--145682214) Fix<y>? yes Free blocks count wrong for group #4442 (214, counted=211). Fix<y>? yes Free blocks count wrong for group #4445 (208, counted=211). Fix<y>? yes Free blocks count wrong (4826, counted=4814). Fix<y>? yes Free inodes count wrong (56170081, counted=56170077). Fix<y>? yes /dev/sdc: ***** FILE SYSTEM WAS MODIFIED ***** /dev/sdc: 10938787/67108864 files (2.3% non-contiguous), 268430642/268435456 blocks PS C:\Users\whshi> wsl -d UBUNTU-20.04-NEW /etc/update-motd.d/90-updates-available: line 7: /usr/share/update-notifier/notify-updates-outdated: No such file or directory run-parts: /etc/update-motd.d/90-updates-available exited with return code 127 ERROR: could not generate new MOTD This message is shown once a day. To disable it please create the /root/.hushlogin file. -bash: export: `Files/Docker/Docker/resources/bin:/mnt/c/Program': not a valid identifier -bash: export: `Files/usbipd-win/:/mnt/c/Users/whshi/AppData/Local/Microsoft/WindowsApps:/mnt/d/Microsoft': not a valid identifier -bash: export: `Code/bin:/mnt/c/Users/whshi/AppData/Local/OpenHarmony/Sdk/9/toolchains:/snap/bin': not a valid identifier root@LAPTOP-U9BLNV2M:/mnt/c/Users/whshi# cd /home/ root@LAPTOP-U9BLNV2M:/home# touch a root@LAPTOP-U9BLNV2M:/home#
参考地址：how-to-repair-a-vhd-mounting-error? the tutorial not work at all! · Issue #10169 · microsoft/WSL