Time Synchronization Between Smc And The Partitions - Fujitsu Siemens Computers SX series User Manual

Functions of the System Management Console Time synchronization between SMC and partitions

4.4 Time synchronization between SMC and the partitions

All instances running on an SX server have their own separate time management system,
but all use the same time. This affects:
The System Management Console
All partitions (BS2000 and, optionally, Solaris)
The optional SKP-SR
This also applies to the SX series entry-level models (see
external time servers" on page
By default, an NTP cluster is configured under these instances via the administration LAN
of the server. Generally, the SMC is the main NTP server. The quality of this NTP server
(stratum) also determines the quality of the BS2000 time emulated by X2000. Without
additional external timers, the SMC is configured as an NTP server with stratum 5 and the
partitions are configured as NTP clients.
The scale for the quality of the NTP server (stratum) ranges from 0 to 15. The best NTP
server quality (level 1) is found on a server with an official time reference, i.e. with a
connected radio clock which receives an official time signal, or a GPS receiver connected
to receive time. For each server which acts, on the one hand, as an NTP client of a better
server and, on the other hand, as a server for additional clients, the stratum value is raised
(therefore devalued) by 1.
The use of an external timer for BS2000 is basically not required as BS2000 automatically
synchronizes with the Solaris time of the X2000 carrier system. When demands on the
precision of the time reference are more stringent, however, the use of an external timer is
recommended for the SMC. When using VM2000, the exact time is implicitly made available
to all VMs.
For external timers the following options come into question:
An NTP time server with the quality of an external timer
A 3920 time server which is connected to the admin LAN
An SKP-SR with a serially-connected radio clock or a 3920 time server
In addition, BS2000 partitions can be integrated into a computer network where the time of
the members is synchronized (DCE cluster or XCS cluster). If S-servers are also available
in this cluster, the SKP-X of these systems should participate in the NTP cluster of the
SX server. If the cluster comprises several SX servers, they should all participate in the
same NTP cluster.
U41272-J-Z385-3-76
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section "Time cluster with
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