在我的/var/log/syslog ，我看到（过滤不相关的部分）：
Dec 30 15:00:10 myhost systemd[1]: Started CUPS Scheduler. Dec 30 15:13:11 myhost systemd[1]: Started CUPS Scheduler. Dec 30 15:26:11 myhost systemd[1]: Started CUPS Scheduler. Dec 30 15:39:12 myhost systemd[1]: Started CUPS Scheduler. Dec 30 15:52:13 myhost systemd[1]: Started CUPS Scheduler. Dec 30 16:05:13 myhost systemd[1]: Started CUPS Scheduler. Dec 30 16:18:14 myhost systemd[1]: Started CUPS Scheduler. Dec 30 16:25:41 myhost systemd[1]: Started CUPS Scheduler. Dec 30 16:31:15 myhost systemd[1]: Started CUPS Scheduler.
也就是说，每隔几分钟，systemd启动CUPS调度程序。 我没有看到关于失败的消息，但是：
# service cups status ● cups.service - CUPS Scheduler Loaded: loaded (/lib/systemd/system/cups.service; enabled; vendor preset: enabled) Active: inactive (dead) since Fri 2016-12-30 18:55:53 CET; 2min 43s ago Docs: man:cupsd(8) Process: 30684 ExecStart=/usr/sbin/cupsd -l (code=exited, status=0/SUCCESS) Main PID: 30684 (code=exited, status=0/SUCCESS)
现在， /var/log/cups/error_log是空的， /var/log/cups/access_log显示：
localhost - - [30/Dec/2016:15:27:21 +0100] "POST / HTTP/1.1" 200 186 Renew-Subscription successful-ok localhost - - [30/Dec/2016:16:25:41 +0100] "POST / HTTP/1.1" 200 186 Renew-Subscription successful-ok localhost - - [30/Dec/2016:17:24:01 +0100] "POST / HTTP/1.1" 200 186 Renew-Subscription successful-ok localhost - - [30/Dec/2016:18:22:21 +0100] "POST / HTTP/1.1" 200 186 Renew-Subscription successful-ok
这可能对应于重新启动。 我实际上没有连接到本机的打印机和扫描仪。
为什么发生这种情况？