當我關閉運行 Ubuntu 16.04 LTS 的電腦時，需要幾秒鐘才能看到Reached target Shutdown控制台上顯示的最終訊息。然而，顯示此訊息後，需要很長時間才能物理關閉。從 中journalctl，我觀察到，在Reached target Shutdown,systemd顯示後 90 秒dev-sda5.swap: Deactivation timed out，正好在 30 分鐘後Reached target Shutdown（交換停用錯誤後的 28:30），它顯示Timed out starting Power-Off和Forcibly powering off as result of failure，就在最終關閉之前。 30 分鐘超時似乎僅在計算機已開啟一段時間（數小時）後才會發生。如果計算機只打開了很短的時間（不到一個小時），它通常會很快關閉。
journalctl案例的最後幾行做快速關閉：
dec 04 09:23:54 sjisjka systemd[1]: dev-.bootchart-proc.mount: Mount process exited, code=exited status=32
dec 04 09:23:54 sjisjka systemd[1]: Failed unmounting /dev/.bootchart/proc.
dec 04 09:23:54 sjisjka systemd[1]: Unmounted /run/user/129.
dec 04 09:23:54 sjisjka systemd[1]: Unmounted /run/user/1000.
dec 04 09:23:54 sjisjka systemd[1]: Stopped target Local File Systems (Pre).
dec 04 09:23:54 sjisjka systemd[1]: Stopped Create Static Device Nodes in /dev.
dec 04 09:23:54 sjisjka systemd[1]: Stopped Remount Root and Kernel File Systems.
dec 04 09:23:54 sjisjka systemd[1]: Reached target Shutdown.
dec 04 09:23:57 sjisjka systemd[1]: Deactivated swap /dev/disk/by-uuid/a092fe32-c536-4c0c-bd2e-416f606b2c33.
dec 04 09:23:57 sjisjka systemd[1]: Deactivated swap /dev/disk/by-path/pci-0000:00:1f.5-ata-1-part5.
dec 04 09:23:57 sjisjka systemd[1]: Deactivated swap /dev/disk/by-id/wwn-0x5002538d40d0e7c8-part5.
dec 04 09:23:57 sjisjka systemd[1]: Deactivated swap /dev/disk/by-id/ata-Samsung_SSD_850_EVO_500GB_S2RBNX0H448728M-part5.
dec 04 09:23:57 sjisjka systemd[1]: Deactivated swap /dev/sda5.
dec 04 09:23:57 sjisjka systemd[1]: Reached target Unmount All Filesystems.
dec 04 09:23:57 sjisjka systemd[1]: Reached target Final Step.
dec 04 09:23:57 sjisjka systemd[1]: Starting Power-Off...
dec 04 09:23:57 sjisjka systemd-udevd[13082]: failed to execute '/lib/udev/socket:@/org/freedesktop/hal/udev_event' 'socket:@/org/freedesktop/hal/udev_event': No such file or directory
dec 04 09:23:57 sjisjka systemd-udevd[13079]: Process 'socket:@/org/freedesktop/hal/udev_event' failed with exit code 2.
dec 04 09:23:57 sjisjka systemd[1]: Shutting down.
dec 04 09:23:57 sjisjka systemd-shutdown[1]: Sending SIGTERM to remaining processes...
dec 04 09:23:57 sjisjka systemd-journald[304]: Journal stopped
-- Reboot --
案例的最後幾行才不是快速關閉：
dec 05 23:55:06 sjisjka systemd[1]: Stopped LSB: ebtables ruleset management.
dec 05 23:55:06 sjisjka systemd[1]: Stopped target Local File Systems.
dec 05 23:55:06 sjisjka systemd[1]: Unmounting /dev/.bootchart/proc...
dec 05 23:55:06 sjisjka systemd[1]: Unmounting /run/user/129...
dec 05 23:55:06 sjisjka systemd[1]: Unmounted /dev/.bootchart/proc.
dec 05 23:55:06 sjisjka systemd[1]: Unmounted /run/user/129.
dec 05 23:55:06 sjisjka systemd[1]: Stopped target Local File Systems (Pre).
dec 05 23:55:06 sjisjka systemd[1]: Stopped Create Static Device Nodes in /dev.
dec 05 23:55:06 sjisjka systemd[1]: Stopped Remount Root and Kernel File Systems.
dec 05 23:55:06 sjisjka systemd[1]: Reached target Shutdown.
dec 05 23:56:36 sjisjka systemd[1]: dev-sda5.swap: Deactivation timed out. Stopping.
dec 05 23:56:36 sjisjka systemd[1]: Deactivated swap /dev/sda5.
dec 05 23:56:36 sjisjka systemd[1]: dev-sda5.swap: Unit entered failed state.
dec 05 23:56:36 sjisjka systemd-udevd[7031]: failed to execute '/lib/udev/socket:@/org/freedesktop/hal/udev_event' 'socket:@/org/freedesktop/hal/udev_event': No such file or directory
dec 05 23:56:36 sjisjka systemd-udevd[7029]: Process 'socket:@/org/freedesktop/hal/udev_event' failed with exit code 2.
dec 06 00:25:03 sjisjka systemd[1]: poweroff.target: Job poweroff.target/start timed out.
dec 06 00:25:03 sjisjka systemd[1]: Timed out starting Power-Off.
dec 06 00:25:03 sjisjka systemd[1]: poweroff.target: Job poweroff.target/start failed with result 'timeout'.
dec 06 00:25:03 sjisjka systemd[1]: Forcibly powering off as result of failure.
dec 06 00:25:03 sjisjka systemd[1]: Shutting down.
dec 06 00:25:03 sjisjka systemd-shutdown[1]: Sending SIGTERM to remaining processes...
dec 06 00:25:03 sjisjka systemd-journald[298]: Journal stopped
這台電腦是 2008 年戴爾電腦，配備 Intel(R) Core(TM)2 Duo CPU、E7300 @ 2.66GHz。它具有 4 GB RAM (4×1GB) 和最新的 448 GB SSD 磁碟。
在作業系統關閉所有服務（或聲稱已這樣做）後，哪個進程或元件負責發送「關閉」命令？我該如何調試這顯然無法正常工作？可能是什麼原因造成的？在撰寫本文時，有Google 搜尋上只有 5 個結果對於「啟動關機逾時」。最有希望的結果是ubuntu 錯誤報告具有相同的症狀，但該案例似乎與cpufreqd我沒有的消息有關。還有一個德語 Linux Mint 線程症狀不同，沒有結論，Redhad錯誤描述它與 NFS 相關，我也沒有使用 NFS。其他結果是沒有上下文的原始日誌，對我沒有任何幫助。