Fujitsu BS2000, User Manual

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Architecture and strategies Time synchronization
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NTP configuration in the Management Cluster
An external time server should be configured in the MUs of the Management Cluster.
●
If no external time server is configured or if it cannot be reached, the time of all units is
synchronized with the local time of the MU1 of the local SE server.
●
If an external time server is configured (MU1 and MU2) and can be reached, all units
(HNC and SU x86) are synchronized with the MU1 of the local SE Server. If the MU1
cannot be reached, all units are synchronized with the MU2 of the local SE server.
In all units, the MUs of the local SE server and the MU1 of the first SE server are entered
as NTP server.
●
The IPv6 address in the network MCNPR is entered.
●
The MU1 in the first SE server receives the stratum value 7.
●
Every additional MU1 receives the stratum value 8.
●
Every MU2 receives the stratum value 9.
Time synchronization in BS2000
On SU x86, the basic software X2000 is initially responsible for the time synchronization.
X2000 emulates the clocks used on /390 architecture, namely the
Time of Day Register
TODR and the SVP clock, for BS2000, the SVP clock always supplying the current Linux
time.
On SU /390, the MU communicating with the SVP of the SU /390 is responsible for the time
synchronization in BS2000. The SVP clock of the SU /390 always receives the current Linux
time from this MU.
BS2000 is automatically synchronized with the SVP clock, and thus with the Linux time. As
the command for reading the SVP time ignores the milliseconds, the time can be inaccurate
by as much as one second. If this inaccuracy is too great, an NTP connection within BS2000
can also make sense.
If the Linux time is synchronized using an NTP server, this automatically also applies for
BS2000. If the NTP server has an NTP server quality with a stratum
Î
4 and the current
time difference is less than one second, BS2000 is shown that the Linux time available is
as accurate as the radio clock (see
SYNCHRONIZATION
in the output of the SHOW-
SYSTEM-INFORMATION INFORMATION=*SYSTEM-TIME-PARAMETER command).
If the Linux time is not synchronized using an NTP server, all the other synchronization
instances in BS2000 (NTP or XCS) can apply.
An NTP instance in BS2000 with a stratum
Î
4 is always higher ranking than an SVP time
with a radio clock (which is equivalent to a Linux time with a stratum
Î
4).