Related elog thread: 16286

I didn't really achieve anything but I'm listing what I've tried.

• I know now that the timesyncd isn't working because systemd-timesyncd is known to have issues when running on a read-only file system. In particular, the service does not have privileges to change the clock or drift settings at /run/systemd/clock or /etc/adjtime.
• The workarounds to these problems are poorly rated/reviews in stack exchange and require me to change the /etc/systmd/timesyncd.conf file but I'm unable to edit this file.
• I know that Paco was able to change these files earlier as the files are now changed and configured to follow a debian ntp pool server which won't work as the FEs do not have internet access. So the conf file needs to be restored to using ntpserver as the ntp server.
• From system messages, the ntpserver is recognized by the service as shown in the second part of 16285. I really think the issue is in file permissions. the file /etc/adjtime has never been updated since 2017.
• I got help from Paco on how to edit files for FE machines. The FE machines directories are exported from fb1:/diskless/root.jessie/
• I restored the /etc/systmd/timesyncd.conf file to how it as before with just servers=ntpserver line. Restarted timesyncd service on all FEs,I tried a few su the synchronization did not happen.
• I tried a few suggestions from stackexchange but none of them worked. The only rated solution creates a tmpfs directory outside of read-only filesystem and uses that to run timesyncd. So, in my opinion, timesyncd  would never work in our diskless read-only file system FE machines.
• One issue in an archlinux discussion ended by the questioner resorting to use opennptd from openBSD distribution. The user claimed that opennptd is simple enough that it can run ntp synchornization on a read-only file system.
• Somehwat painfully, I 'kind of' installed the openntpd tool in the fb1:/diskless/root.jessie directory following directions from here. I had to manually add user group and group for the FEs (which I might not have done correctly). I was not able to get the openntpd daemon to start properly after soe tries.
• I restored everything back to how it was and restarted timesyncd in c1sus even though it would not do anything really.