昨日のDebian 8.5クラッシュログを収集する方法は？

昨日初めてDebian 8.5がクラッシュしました。多くのプロセスがアクティブになり（Google Chrome 52.x、Matlab 2016a、...）、システムが突然クラッシュします。画面が暗くなり、ユーザー操作は許可されません。唯一のオプションは再起動です。

より詳細に研究するためにログを収集したいと思います。私の考え

• dmesg | grepしかし、特定の間隔を取得する方法
• log/ディレクトリがどこかに存在します/

GAD3Rテスト回答

コマンドを学ぶjournalctl --since yesterday

• 中にエラーが発生しました。journalctl --since yesterday | grep error | less

   Oct 01 16:30:40 masi kernel: tpm_crb: probe of MSFT0101:00 failed with error -16
   Oct 01 16:30:40 masi kernel: EXT4-fs (sda2): re-mounted. Opts: errors=remount-ro
   Oct 01 16:30:40 masi kernel: iwlwifi 0000:01:00.0: Direct firmware load for iwlwifi-7265D-21.ucode failed with error -2
   ...
   Oct 01 16:30:41 masi apache2[1053]: The Apache error log may have more information.
   Oct 01 16:30:42 masi gdm-Xorg-:0[1427]: (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
   Oct 01 16:30:53 masi org.a11y.Bus[1599]: g_dbus_connection_real_closed: Remote peer vanished with error: Underlying GIOStream returned 0 bytes on an async read (g-io-error-quark, 0). Exiting.
   ...
   Oct 01 16:30:53 masi gnome-session[1595]: g_dbus_connection_real_closed: Remote peer vanished with error: Underlying GIOStream returned 0 bytes on an async read (g-io-error-quark, 0). Exiting.
   Oct 01 16:30:53 masi ca.desrt.dconf[1599]: g_dbus_connection_real_closed: Remote peer vanished with error: Underlying GIOStream returned 0 bytes on an async read (g-io-error-quark, 0). Exiting.
   Oct 01 16:31:20 masi gnome-session[1775]: (tracker-extract:1960): Tracker-WARNING **: Task for 'file:///home/masi/Documents/(Compu.djvu' finished with error:
   Could not get any metadata for uri:'file:///1...1.djvu' and mime:'image/vnd.djvu'
   Could not get any metadata for uri:'file:///home/masi/Documents/Programming/CDC..1.svg' and mime:'image/svg+xml'
   Oct 01 16:31:20 masi gnome-session[1775]: (tracker-extract:1960): Tracker-WARNING **: Task for 'file:///home/masi/Documents/Physics/0441/r328_1.raw' finished with error: Could not get any metadata for
   Oct 02 15:45:21 masi gnome-session[1775]: (nm-applet:1964): libnm-glib-WARNING **: replace_settings: error updating connection /org/freedesktop/NetworkManager/Settings/6 settings: (1) ipv4.routes: 1. route is invalid
   ...
   Oct 02 15:54:28 masi org.freedesktop.Telepathy.AccountManager[1818]: (process:1906): libnm-glib-WARNING **: replace_settings: error updating connection /org/freedesktop/NetworkManager/Settings/6 settings: (1) ipv4.routes: 1. route is invalid
   ...           
   Oct 02 16:51:08 masi org.gtk.Private.UDisks2VolumeMonitor[1818]: index_parse.c:191: indx_parse(): error opening /media/masi/MasiWeek/BDMV/index.bdmv
   Oct 02 16:51:08 masi org.gtk.Private.UDisks2VolumeMonitor[1818]: index_parse.c:191: indx_parse(): error opening /media/masi/MasiWeek/BDMV/BACKUP/index.bdmv
   Oct 02 17:55:02 masi kernel: jxbrowser-chrom[26948]: segfault at 39 ip 00007ff33300d760 sp 00007fff715c0c38 error 6 in libjxbrowser-chromium-lib.so[7ff3322ea000+7676000]
   Oct 02 18:15:51 masi gnome-session[1775]: Gjs-Message: JS LOG: Received error from DBus search provider org.gnome.Photos.desktop during GetResultMetas: Gio.DBusError: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name :1.383 was not provided by any .service files
   Oct 02 23:00:24 masi org.gtk.vfs.Daemon[1818]: ** (process:2021): WARNING **: send_infos_cb: No such interface 'org.gtk.vfs.Enumerator' on object at path /org/gtk/vfs/client/enumerator/5 (g-dbus-error-quark, 19)
   ...
   Oct 02 23:08:49 masi org.gtk.vfs.Daemon[1818]: ** (process:2021): WARNING **: send_done_cb: No such interface 'org.gtk.vfs.Enumerator' on object at path /org/gtk/vfs/client/enumerator/9 (g-dbus-error-quark, 19)
  

• 警告するjournalctl --since yesterday | grep warning | less

    Oct 01 16:30:42 masi gdm-Xorg-:0[1427]: (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
    Oct 01 17:05:24 masi gnome-session[1775]: Window manager warning: Invalid WM_TRANSIENT_FOR window 0x280002f specified for 0x2800038 ( ).
    Oct 02 22:23:32 masi gnome-session[1775]: Window manager warning: Window 0x2801c66 (HG_Peer_Of) sets an MWM hint indicating it isn't resizable, but sets min size 1 x 1 and max size 2147483647 x 2147483647; this doesn't make much sense.
    ... [thousands of this warning]
  

• 出力root@masi:/home/# timedatectl status

        Local time: Sun 2016-10-02 23:15:57 EEST
    Universal time: Sun 2016-10-02 20:15:57 UTC
          RTC time: Sun 2016-10-02 20:15:57
         Time zone: Europe/Helsinki (EEST, +0300)
       NTP enabled: no
  NTP synchronized: no
   RTC in local TZ: no
        DST active: yes
   Last DST change: DST began at
                    Sun 2016-03-27 02:59:59 EET
                    Sun 2016-03-27 04:00:00 EEST
   Next DST change: DST ends (the clock jumps one hour backwards) at
                    Sun 2016-10-30 03:59:59 EEST
                    Sun 2016-10-30 03:00:00 EET
  

OS：Debian 8.5 64ビット
Linuxカーネル：スレッドの説明に従って4.6用のバックポートを設定するここ
ハードウェア：ASUS Zenbook UX303UA