仮想ディスク内のパーティションをマウント

仮想ディスク上のgrub設定を編集したときのメモ。

[root@localhost ~]# fdisk -u -l /var/lib/libvirt/images/centos5_3-sda.img
You must set cylinders.
You can do this from the extra functions menu.

Disk /var/lib/libvirt/images/centos5_3-sda.img: 0 MB, 0 bytes
255 heads, 63 sectors/track, 0 cylinders, total 0 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x0003cb19

                                    Device Boot      Start         End      Blocks   Id  System
/var/lib/libvirt/images/centos5_3-sda.img1   *          63      192779       96358+  83  Linux
/var/lib/libvirt/images/centos5_3-sda.img2          192780    14811929     7309575   83  Linux
/var/lib/libvirt/images/centos5_3-sda.img3        14811930    16771859      979965   82  Linux swap / Solaris
Partition 3 has different physical/logical endings:
     phys=(1023, 254, 63) logical=(1043, 254, 63)
[root@localhost ~]# mount -o loop,offset=`expr 192780 \* 512` /var/lib/libvirt/images/centos5_3-sda.img /mnt
# mount -o loop,offset=`expr     63 \* 512` /var/lib/libvirt/images/centos5_3-sda.img /mnt/boot

[root@localhost ~]# cat /mnt/boot/grub/menu.lst
# Enable console output via the serial port. unit 0 is /dev/ttyS0, unit 1 is /dev/ttyS1...
serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1
terminal --timeout=15 serial console

kernel          /vmlinuz-2.6.26-2-amd64 root=/dev/vda2 ro quiet
↓
kernel          /vmlinuz-2.6.26-2-amd64 root=/dev/vda2 ro quiet console=tty0 console=ttyS0,115200n8