systemd-remount-fs.service, systemd-remount-fs — Remount root and kernel file systems
systemd-remount-fs.service is an
early boot service that applies mount options listed in
to the root file system, the
/usr file system,
and the kernel API file systems. This is required so that the
mount options of these file systems — which are pre-mounted by
the kernel, the initial RAM disk, container environments or system
manager code — are updated to those listed in
/etc/fstab. This service ignores normal file
systems and only changes the root file system (i.e.
/usr and the virtual
kernel API file systems such as
service executes no operation if
does not exist or lists no entries for the mentioned file
For a longer discussion of kernel API file systems see API File Systems.