The correct syntax for mounting sshfs shares at boot, in the /etc/fstab file is
USERNAME@HOSTNAME_OR_IP:/REMOTE/DIRECTORY /LOCAL/MOUNTPOINT fuse.sshfs _netdev,user,idmap=user,transform_symlinks,identityfile=/home/USERNAME/.ssh/id_rsa,allow_other,default_permissions,uid=USER_ID_N,gid=USER_GID_N 0 0
It is an adaptation to non-systemd distros of the instructions contained here. If you are instead on a systemd distro (Arch, Fedora, OpenSUSE,...), the suitable instruction is:
USERNAME@HOSTNAME_OR_IP:/REMOTE/DIRECTORY /LOCAL/MOUNTPOINT fuse.sshfs x-systemd.automount,_netdev,user,idmap=user,transform_symlinks,identityfile=/home/USERNAME/.ssh/id_rsa,allow_other,default_permissions,uid=USER_ID_N,gid=USER_GID_N 0 0
In my Windows 10 mounting home directory of remote ssh server worked in user's powershell using command
net use S: \\sshfs\user@host\.
Note single dot at the end! Without the dot it did not work. For mounting root folder, use
net use S: \\sshfs\user@host\..\..
The same works (but with different syntax) on Windows Explorer -> This PC -> Map network drive. In my system I had to enter the path with leading two backward slashes:
for root
\\sshfs\user@host/../..
for home
\\sshfs\user@host/
Note forward slashes here! You may need to mark "Use different credentials" and enter username / password in several subsequent dialogue boxes.
Best Answer
Because umount only allows root to unmount regular filesystems.
You can, however, unmount any FUSE filesystem (inclusing sshfs) without using sudo: