Fedora18 频繁死机，开一会就特别热，鼠标键盘都无响应。在WIN7下散热良好，极少出现死机情况。
现在删除firefox 更换Chrome 更换KDE
yum groupinstall kde-desktop
安装中文：
yum install kde-i18n-Chinese.noarch
yum install kde-l10n-Chinese.noarch
然后注销，登陆的时候底下有选项，选择KDE,
输入账号密码，登陆就切换到KDE了
看看能不能解决。
这个方法好了一些。用了一天没死。打开google浏览器的时候，同时开多个页面看视频，散热口很快变烫。尝试关闭独立显卡。命令如下：
echo IGD > /sys/kernel/debug/vgaswitcheroo/switch
echo OFF > /sys/kernel/debug/vgaswitcheroo/switch
关闭后查看关闭结果
cat /sys/kernel/debug/vgaswitcheroo/switch
如果显示如下：
0:IGD:+:Pwr:0000:00:02.0
1:DIS: :Off:0000:01:00.0
证明独显关闭成功。
将以下命令添加到/etc/bashrc结尾处，重启电脑
#todo: wulong close graphics card
echo IGD >/sys/kernel/debug/vgaswitcheroo/switch ;echo OFF > /sys/kernel/debug/vgaswitcheroo/switch
#endif
再用一阵，看看效果。总是热得电脑死机. fedora的问题还真多。
重启运行提示没有运行权限，但是独立显卡确实关掉了。
刚才又死机了。正常上网，忽然风扇飞转，感觉不好赶快reboot，然后就死机，风扇仍然飞转，热得烫手，只能硬关机，心疼电脑。查看/var/log/message
May 27 23:42:10 localhost kernel: [ 3384.954712] Disabling IRQ #17
May 27 23:42:11 localhost kernel: [ 3385.452900] ath: phy0: Failed to stop TX DMA, queues=0x10f!
May 27 23:42:11 localhost kernel: [ 3385.466319] ath: phy0: DMA failed to stop in 10 ms AR_CR=0xffffffff AR_DIAG_SW=0xffffffff DMADBG_7=0xffffffff
May 27 23:42:11 localhost kernel: [ 3385.466385] ath: phy0: Could not stop RX, we could be confusing the DMA engine when we start RX up
May 27 23:42:11 localhost kernel: [ 3385.584248] ath: phy0: Chip reset failed
May 27 23:42:11 localhost kernel: [ 3385.584257] ath: phy0: Unable to reset channel, reset status -22
May 27 23:42:11 localhost kernel: [ 3385.584325] ath: phy0: Unable to set channel
May 27 23:53:38 localhost systemd-logind[526]: Linked /tmp/.X11-unix/X0 to /run/user/1000/X11-display.
May 27 23:53:38 localhost gnome-session[1049]: WARNING: Detected that screensaver has left the bus
May 27 23:53:38 localhost gnome-session[1049]: CRITICAL: gsm_manager_set_phase: assertion `GSM_IS_MANAGER (manager)' failed
May 27 23:53:38 localhost gdm-simple-slave[583]: WARNING: Failed to remove slave program access to the display. Trying to proceed.
May 27 23:53:54 localhost dbus-daemon[544]: ** Message: No devices in use, exit
May 27 23:53:58 localhost systemd-logind[526]: Removed session 1.
May 27 23:53:59 localhost systemd[1]: Cannot add dependency job for unit mdmonitor-takeover.service, ignoring: Unit mdmonitor-takeover.service failed to load: No such file or directory. See system logs and 'systemctl status mdmonitor-takeover.service' for details.
May 27 23:53:59 localhost systemd[1]: Starting CUPS Printing Service...
May 27 23:53:59 localhost systemd[1]: Started CUPS Printing Service.
May 27 23:54:04 localhost rtkit-daemon[1185]: Successfully made thread 1465 of process 1465 (/usr/bin/pulseaudio) owned by '1000' high priority at nice level -11.
May 27 23:54:05 localhost dbus-daemon[544]: dbus[544]: [system] Activating via systemd: service name='org.bluez' unit='dbus-org.bluez.service'
May 27 23:54:05 localhost dbus-daemon[544]: dbus[544]: [system] Activation via systemd failed for unit 'dbus-org.bluez.service': Unit dbus-org.bluez.service failed to load: No such file or directory. See system logs and 'systemctl status dbus-org.bluez.service' for details.
May 27 23:54:05 localhost dbus[544]: [system] Activating via systemd: service name='org.bluez' unit='dbus-org.bluez.service'
May 27 23:54:05 localhost dbus[544]: [system] Activation via systemd failed for unit 'dbus-org.bluez.service': Unit dbus-org.bluez.service failed to load: No such file or directory. See system logs and 'systemctl status dbus-org.bluez.service' for details.
May 27 23:54:05 localhost pulseaudio[1465]: [pulseaudio] bluetooth-util.c: org.bluez.Manager.ListAdapters() failed: org.freedesktop.systemd1.LoadFailed: Unit dbus-org.bluez.service failed to load: No such file or directory. See system logs and 'systemctl status dbus-org.bluez.service' for details.
上面就是错误
一.蓝牙问题
dbus[544]: [system] Activation via systemd failed for unit 'dbus-org.bluez.service'
老外说这样解决，参考https://bbs.archlinux.org/viewtopic.php?id=155714
1.首先查一下蓝牙状态
[root@localhost wulong]# systemctl status dbus-org.bluez.service
dbus-org.bluez.service
Loaded: error (Reason: No such file or directory)
Active: inactive (dead)
2.无法检测蓝牙状态，那么允许检测蓝牙状态
[root@localhost wulong]# systemctl enable bluetooth.service
Failed to issue method call: File exists
3.查看设置结果
[root@localhost wulong]# systemctl status dbus-org.bluez.service
bluetooth.service - Bluetooth service
Loaded: loaded (/usr/lib/systemd/system/bluetooth.service; enabled)
Active: inactive (dead)
二.解决这个问题
May 27 23:53:59 localhost systemd[1]: Cannot add dependency job for unit mdmonitor-takeover.service, ignoring: Unit mdmonitor-takeover.service failed to load: No such file or directory. See system logs and 'systemctl status mdmonitor-takeover.service' for details.
参考这里
https://bugzilla.redhat.com/show_bug.cgi?id=901651
1.查看一下
[root@localhost log]# ls /etc/systemd/system/sysinit.target.wants/
lvm2-monitor.service mdmonitor-takeover.service
[root@localhost log]# ls -l /etc/systemd/system/sysinit.target.wants/mdmonitor-takeover.service
lrwxrwxrwx. 1 root root 46 May 23 05:23 /etc/systemd/system/sysinit.target.wants/mdmonitor-takeover.service -> /lib/systemd/system/mdmonitor-takeover.service
2.看到mdmonitor-takeover.service，把它移除
[root@localhost log]# rm /etc/systemd/system/sysinit.target.wants/mdmonitor-takeover.service
先这样。继续测试。把centos和ubuntu都下载下来。fedora再这样就换系统。小白鼠不好当，太浪费时间了。
ubuntu关机的时候死机：http://www.linuxdiyf.com/linux/13968.html
尝试解决ubuntu12.10无线联网不定时死机问题：http://www.linuxdiyf.com/linux/13967.html
ubuntu12.04断网后忽然死机解决方法：http://www.linuxdiyf.com/linux/13965.html
怎样处理Linux死机：http://www.linuxdiyf.com/linux/62.html
详解Linux死机后的安全重启：http://www.linuxdiyf.com/linux/338.html