linux patition and grub

分区、格式化、挂载

开机启动时自动挂载某个分区，需要修改文件：/etc/fstab则可。

查看某个分区的文件系统类型：file -s /dev/sda2

将某个分区格式化，指定格式的文件系统：

sudo mkfs.ext4 /dev/sda2 //将/dev/sda2盘格式化为ext4格式

将格式化的分区挂在到系统某个路径上：

mount -t ext4 /dev/sda2 ~/workspace

硬盘分区情况分析

[root@localhost grub]# fdisk -l

Disk /dev/sda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0xc001c001

   Device Boot      Start         End      Blocks   Id  System
   /dev/sda1               1        2432    19535008+  83  Linux
   /dev/sda2            2433        3040     4883760   83  Linux
   /dev/sda3            3041        5472    19535040   8e  Linux LVM
   /dev/sda4            5473        9729    34194352+   5  Extended
   /dev/sda5            7905        9606    13671283+   b  W95 FAT32
   /dev/sda6            9607        9729      987966   82  Linux swap / Solaris
   /dev/sda7   *        5473        5498      204800   83  Linux

   Partition table entries are not in disk order

   Disk /dev/dm-0: 8388 MB, 8388608000 bytes
   255 heads, 63 sectors/track, 1019 cylinders
   Units = cylinders of 16065 * 512 = 8225280 bytes
   Disk identifier: 0x00000000

   Disk /dev/dm-0 doesn't contain a valid partition table

   Disk /dev/dm-1: 10.5 GB, 10485760000 bytes
   255 heads, 63 sectors/track, 1274 cylinders
   Units = cylinders of 16065 * 512 = 8225280 bytes
   Disk identifier: 0x00000000

   Disk /dev/dm-1 doesn't contain a valid partition table

   Disk /dev/dm-2: 1128 MB, 1128267776 bytes
   255 heads, 63 sectors/track, 137 cylinders
   Units = cylinders of 16065 * 512 = 8225280 bytes
   Disk identifier: 0x00000000

   Disk /dev/dm-2 doesn't contain a valid partition table

可以看到，一共有4个Disk被检测到了，分别是：

Disk /dev/sda
Disk /dev/dm-0
Disk /dev/dm-1
Disk /dev/dm-2

其中，我们可以看到磁盘/dev/sda的分区情况。“Partition table entries are not in disk order”的含义是，分区命名的顺序和其中磁盘中的位置并不一致。/dev/sda7 的分区数是最大的，但是，其实他再磁盘中，cylinders是从 5473到5498，再逻辑分区/dev/sda5的前面，占据我们的扩展分区/dev/sda4的最开始的位置。

UUID和grub

查看硬盘各分区的UUID，用命令ls -al /dev/disk/by-uuid 查看你的所有的硬盘的UUID信息！

[ny@localhost disk]$ pwd
/dev/disk
[ny@localhost disk]$ ll
total 0
drwxr-xr-x 2 root root 520 2011-04-18 04:33 by-id
drwxr-xr-x 2 root root 300 2011-04-18 04:33 by-path
drwxr-xr-x 2 root root 240 2011-04-18 04:33 by-uuid
[ny@localhost disk]$ ll by-uuid/
total 0
lrwxrwxrwx 1 root root 11 2011-04-18 04:33 127ad9a9-694b-478d-9d57-6973dcc348a3 -> ../../sda13
lrwxrwxrwx 1 root root 10 2011-04-18 04:33 15678ede-8363-4e55-bd61-fba7c4879a88 -> ../../sda8
lrwxrwxrwx 1 root root 10 2011-04-18 04:33 19df1940-6796-4b8b-844e-50d7811349b6 -> ../../sda7
lrwxrwxrwx 1 root root 11 2011-04-18 04:33 1b820644-b312-416f-8837-4acbf39334e5 -> ../../sda10
lrwxrwxrwx 1 root root 11 2011-04-18 04:33 224ee11f-029f-45eb-9374-7a29429bd696 -> ../../sda11
lrwxrwxrwx 1 root root 10 2011-04-18 04:33 8E84E98B84E975DD -> ../../sda1
lrwxrwxrwx 1 root root 11 2011-04-18 04:33 902886c5-a501-471d-b09d-e8a05d2b7a82 -> ../../sda12
lrwxrwxrwx 1 root root 10 2011-04-18 04:33 C4CC0EEECC0EDA96 -> ../../sda5
lrwxrwxrwx 1 root root 10 2011-04-18 04:33 d87dceaa-5e15-49fe-b5f6-d55f3f1a8bb5 -> ../../sda9
lrwxrwxrwx 1 root root 10 2011-04-18 04:33 F02D-ECB2 -> ../../sda6

安装好之后如果只有XP与Ubuntu 9.10的启动菜单而没有Fedora 12的菜单，先进入Fedora系统，打开终端，编辑menu.lst，使用Linux下查看UUID方法这一文的方法，找出Ubuntu 9.10安装分区的UUID。

进入Fedora 12系统，在menu.lst中加入

title  Ubuntu 9.10, kernel 2.6.28-11-generic (recovery mode)
uuid  9f3ad068-eaf0-484d-bfc0-4c13fd7a79ae
kernel  /boot/vmlinuz-2.6.28-11-generic root=UUID=9f3ad068-eaf0-484d-bfc0-4c13fd7a79ae ro  single
initrd  /boot/initrd.img-2.6.28-11-generic

参考文章[http://www.fedoraforum.org/forum/showthread.php?t=252004 What eats my disk space]。