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 fstab(5), or
       gathered from the partition table (when systemd-gpt-auto-generator(8) is active) 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 initrd, container environments or system
       manager code — are updated to those configured in /etc/fstab and the other sources. 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 no configuration is
       found (/etc/fstab does not exist or lists no entries for the mentioned file systems, or the partition
       table does not contain relevant entries).

       For a longer discussion of kernel API file systems see APIFileSystems[1].

       Note: systemd-remount-fs.service is usually pulled in by systemd-fstab-generator(8), hence it is also
       affected by the kernel command line option fstab=, which may be used to disable the generator. It may
       also be pulled in by systemd-gpt-auto-generator(8), which is affected by systemd.gpt_auto and other
       options.

       systemd-remount-fs.service, systemd-remount-fs - Remount root and kernel file systems

        1. API File Systems
           https://systemd.io/API_FILE_SYSTEMS

systemd 257.7                                                                      SYSTEMD-REMOUNT-FS.SERVICE(8)

systemd(1), fstab(5), mount(8), systemd-fstab-generator(8), systemd-gpt-auto-generator(8)

       systemd-remount-fs.service

       /usr/lib/systemd/systemd-remount-fs