systemd-remount-fs.service, systemd-remount-fs — Remount root and kernel file systems
systemd-remount-fs.service
/usr/lib/systemd/systemd-remount-fs
systemd-remount-fs.service is an
early boot service that applies mount options listed in
fstab(5)
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 /proc,
/sys or /dev. This
service executes no operation if /etc/fstab
does not exist or lists no entries for the mentioned file
systems.
For a longer discussion of kernel API file systems see API File Systems.