On Wed, Feb 08, 2023 at 07:15:27PM +0100, Paul de Weerd wrote: > On Wed, Feb 08, 2023 at 04:50:32PM +0100, Jan Stary wrote: > | On Feb 08 13:56:18, [email protected] wrote: > | > 1) close any open files stored there > | > 2) make sure no process has the media as $PWD (as in, cd away from there, > | > and really a variation on the first) > | > 3) issue at least one sync command (some folklore will insist on three) > | > 4) umount the media from wherever it was mounted > | > | 4 takes care of 1,2,3, right? > > Not if the kernel has a file open on it (e.g. a swap file [1]) or if > there's another mount somewhere in the filesystem you're trying to > unmount (a special case of the first condition, I guess). > > [weerd@kale] $ doas mount /dev/sd3a /mnt > [weerd@kale] $ doas mkdir /mnt/deeper > [weerd@kale] $ doas mount /dev/sd3d /mnt/deeper > [weerd@kale] $ doas dd if=/dev/zero of=/mnt/swap bs=1M count=4096 > [weerd@kale] $ doas swapon /mnt/swap > > The kernel is not going to let you `umount /mnt`, and forcibly > removing the device is very likely going to lead to amazing new > learning opportunities. > > So, yeah, as people have stated .. the way to safely remove a USB > drive from your system depends on what you were using the USB drive > for. For the generic case, where we have no clue what OP was doing: > shut down your machine first and remove the device then. > Does shut down save you from the case above? Shut down is the same as umount -f ?
Nola -- Nils Ola Nilsson, 🐞 [email protected]
