MJ Ray markj@cloaked.freeserve.co.uk writes:
John Fremlin:
MJ Ray markj@cloaked.freeserve.co.uk writes:
Hold AltGr and SysRq, then tap out s u u b (sync, unmount, unmount, boot)
You should sync after umount too or else you'll probably get spurious fscks on boot (it needs to write a clean umount flag to the superblock)
Surely a sync won't do anything to a read-only disk? (OK, I lied: "u" is actually remount-read-only.)
Mounting read only obviously does not mean anything about the disk
When you umount or mount a read-write ext2 filesystem read-only then a flag is set in the superblock to say that the filesystem was cleanly umounted. You need to write this flag out, so you should sync rather than leave it to more random chance