man/man1/ast_umount.html man page

umount - unmount filesystems

umount unmounts one or more currently mounted filesystems, which can be specified either as mounted-on directories or filesystems.

-a, --all: Operate on all filesystems in the filesystem table. The --host and --type options can be used to match parts of the table.
-f, --show|fake: Display but do not execute the underlying umount(2) system calls.
-h, --hosts=[!]host,...: Limit the filesystem table scan to entries matching the host names. A leading ! inverts the match sense.
-M, --mtab|fstab=file: Use file instead of the default filesystem table.
-b, --omit=[!]type,...: Omit filesystem table entries matching any of the type names.
-t|T, --types=[!]type,...: Limit the filesystem table scan to entries matching the type names. A leading ! inverts the match sense.
-m, --multiplex|nproc: Distribute multiple mounts across nproc processes. Ignored by this implementation.
-P, --prefix=string: Ignored by this implementation.
-v, --verbose: Ignored by this implementation.

df(1), mount(1), umount(2), fstab(4)