这2个问题遇到多次了，今天终于搞明白了
1.如果报错为
Error loading keymap /var/tmp/server-0.xkm
Couldn't load XKB keymap, falling back to pre-XKB keymap
说明硬盘满了，没地方写/tmp下的临时文件，白痴吧哈哈哈
2.如果报错为
unable to find a valid framebuffer device
failed to open framebuffer device
查找/etc/X11/XF86Config-4, 有一句
Option "UseFBDev" "yes"
改为no,不用framebuffer就OK了