【Linux】查看、升级系统、kernel版本

1.      An OS may havemultiple kernels with different versions installed. Find out which version youare using:

   root@symantec-virtual-machine:~# uname -r

3.8.0-22-generic

2.       Find out whichOS you are using:

root@symantec-virtual-machine:~# cat /etc/issue

Ubuntu 13.04 \n \l

 

Or

 

root@symantec-virtual-machine:~# lsb_release -a

No LSB modules are available.

Distributor ID: Ubuntu

Description:    Ubuntu 13.04

Release:        13.04

Codename:       raring

3.      Find out 32 or 64bit OS

root@symantec-virtual-machine:~#arch

x86_64

4.      Sometimes you needto select the correct kernel version every time system boot. To avoid thiseffort, you can modify/boot/grub/menu.lst (RedHat,Suse, CentOS, Oracle) or/boot/grub/grub.cfg (Debian,Ubuntu).

Find set default=in /boot/grub/grub.cfg,changethe corresponding number between quotes to the one you want. For example,set default=”1”for the second ‘menuentry’ kernel. (the first‘menuentry’ is 0, and so on). Please note that some menuentry are nested as a sub-menuentry, so the order may not correspondto number. Editing grub.cfg may be needed.

 

 

Find default=in /boot/grub/menu.lst,changethe corresponding number to the one you want. For example,default=1 for the second ‘title’ kernel. (the first ‘title’ is 0,and so on)

               

               When you edit these two files, make a snapshot FIRST.

5.      Some terms: ‘i686’,’i386’ or ‘i586’ means 32 bit, ‘x86_64’ means 64 bit.