...these storage daemons are started from the initramfs, stay running all the time during normal operation and are terminated only after we returned control back to the initramfs and by the initramfs. As such, storage daemons involved with maintaining the root file system storage conceptually are more like kernel threads than like normal system services: from the perspective of the init system (i.e. systemd) these services have been started before systemd got initialized and stay around until after systemd is already gone.
But, isn't the initramfs unmounted once systemd starts? I can't see the initramfs mounted anywhere on my Fedora 28 system.[*]
Where is the filesystem that "Root Storage Daemons" run from?
And what does it look like from their point of view? For example, can they access a fully-featured
/dev during runtime?
[*] There is a directory
/run/initramfs, but it is not a separate ram filesystem (tmpfs mount). It is empty except for a couple of directories with no files, and one file
rwtab which lists the directory names.
$ findmnt -T /run/initramfs TARGET SOURCE FSTYPE OPTIONS /run tmpfs tmpfs rw,nosuid,nodev,seclabel,mode=755 $ find /run/initramfs -type d /run/initramfs /run/initramfs/state /run/initramfs/state/var /run/initramfs/state/var/lib /run/initramfs/state/var/lib/dhclient /run/initramfs/state/etc /run/initramfs/state/etc/sysconfig /run/initramfs/state/etc/sysconfig/network-scripts /run/initramfs/log $ find /run/initramfs -not -type d /run/initramfs/rwtab /run/initramfs/.need_shutdown $ cat /run/initramfs/rwtab files /etc/sysconfig/network-scripts files /var/lib/dhclient $ cat /run/initramfs/.need_shutdown $