Do I need ntpd
daemon / service on an LAMP server running Linux Debian 8.3?
I have already disabled some obvious services, but I am not sure about this one.
A typical single LAMP doesn't usually need a full-blown NTP server - to keep your time accurate add a ntpd -q
job to run every day.
You need an NTP server when more accurate time synchronization is required (like in a case of cloud-based service, distributed along a number of instances) or when your software have issues with jumping clocks (since ntpdate
(which actually is deprecated in favor of ntpd -q
) will directly set the time instead of slowly adjusting it).
If you choose to run ntpd, make sure you add a firewall rule to block incoming connections, since it is a widely-known target for NTP Amplification DDoS attack - having it open to the wild will cause high traffic usage and abuse letters to your hosting company. Run ntpd -q
once at startup before starting ntpd to get the benefits of the better tool.
ntpdate
daily or hourly. Computer clocks drift and being confidant in the times in your logs is nice.
ntpd
becoming a target for this. Also, ntpdate
will be less accurate, it will not discipline the clock to minimize skew and for errors greater then 0.5 seconds, it will directly set the time instead of slowly adjusting it, which can cause issues with some software that doesn't like jumping clocks. Run ntpdate
once at startup before starting ntpd
and then get the benefits of the better tool. Oh, and ntpdate
is deprecated and will go away at some point and ntpd -q
will do it's job.
ntpd
. In the spirit of avoiding premature optimization, surely you have bigger priorities?