Linux对EXT3分区大小进行无损更改的步骤 （2）

3、扩大一个ext3分区

 

在这里，我们拥有一个大约是6GB的/dev/sda1分区，在它后面，有一个大约 4GB的未用空间（刚刚分出来的，呵呵）。现在，我们要做的就是把这4GB的空闲空间增加到/dev/sda1分区中。请注意，如果这4GB的空余空间不 在/dev/sda1后面，而是在硬盘的其它地方，就无法实现这个目的！

首先，我们收集一些当前分区的资料。

 

df

 

Filesystem 1K-blocks Used Available Use% Mounted on

/dev/sda1 6047868 4224140 1639408 73% /

varrun 95480 132 95348 1% /var/run

varlock 95480 0 95480 0% /var/lock

udev 10240 52 10188 1% /dev

devshm 95480 0 95480 0% /dev/shm

lrm 95480 17580 77900 19% /lib/modules/2.6.17-10-generic/volatile

 

df -B 4k

 

Filesystem 4K-blocks Used Available Use% Mounted on

/dev/sda1 1511967 1056035 409852 73% /

varrun 23870 33 23837 1% /var/run

varlock 23870 0 23870 0% /var/lock

udev 2560 13 2547 1% /dev

devshm 23870 0 23870 0% /dev/shm

lrm 23870 4395 19475 19% /lib/modules/2.6.17-10-generic/volatile

 

df -h

 

Filesystem Size Used Avail Use% Mounted on

/dev/sda1 5.8G 4.1G 1.6G 73% /

varrun 94M 132K 94M 1% /var/run

varlock 94M 0 94M 0% /var/lock

udev 10M 52K 10M 1% /dev

devshm 94M 0 94M 0% /dev/shm

lrm 94M 18M 77M 19% /lib/modules/2.6.17-10-generic/volatile

 

fdisk -l

 

 

Disk /dev/sda: 10.7 GB, 10737418240 bytes

255 heads, 63 sectors/track, 1305 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

 

Device Boot Start End Blocks Id System

/dev/sda1 * 1 789 6337611 83 Linux

/dev/sda2 1248 1305 465885 5 Extended

/dev/sda5 1248 1305 465853+ 82 Linux swap / Solaris

 

fdisk -s /dev/sda1

 

6337611

 

然后，我们需要关闭系统，并启动到我们的Knoppix Live-CD（或者rescue系统）中：

shutdown -r now

 

之后，切换用户：

su

 

卸载sda1:

umount /dev/sda1

 

然后执行：

fsck -n /dev/sda1

 

输出：

fsck 1.38 (30-Jun-2005)

e2fsck 1.38 (30-Jun-2005)

/dev/sda1: clean, 159036/765536 files, 1080014/1536000 blocks

 

然后是：

tune2fs -O ^has_journal /dev/sda1

 

输出:

tune2fs 1.38 (30-Jun-2005)

 

接下来运行：

fdisk /dev/sda

 

输出：

 

(Yes, it's /dev/sda, not /dev/sda1.)

 

The number of cylinders for this disk is set to 1305.

There is nothing wrong with that, but this is larger than 1024,

and could in certain setups cause problems with:

1) software that runs at boot time (e.g., old versions of LILO)

2) booting and partitioning software from other OSs

(e.g., DOS FDISK, OS/2 FDISK)

 

Type m to get a list of all commands:

 

Command (m for help): m

Command action

a toggle a bootable flag

b edit bsd disklabel

c toggle the dos compatibility flag

d delete a partition

l list known partition types

m print this menu

n add a new partition

o create a new empty DOS partition table

p print the partition table

q quit without saving changes

s create a new empty Sun disklabel

t change a partition's system id

u change display/entry units

v verify the partition table

w write table to disk and exit

x extra functionality (experts only)

 

我们来打印分区表：

Command (m for help): p

 

Disk /dev/sda: 10.7 GB, 10737418240 bytes

255 heads, 63 sectors/track, 1305 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

 

Device Boot Start End Blocks Id System

/dev/sda1 * 1 789 6337611 83 Linux

/dev/sda2 1248 1305 465885 5 Extended

/dev/sda5 1248 1305 465853+ 82 Linux swap / Solaris

 

现在，删除第一个分区：

Command (m for help): d

Partition number (1-5): 1

 

然后创建一个新的sda1分区,大体事项和缩小分区步骤一样：

Command (m for help): n

Command action

l logical (5 or over)

p primary partition (1-4)

p

Partition number (1-4): 1

 

现在就该确定最开始和末尾的柱面号，首先输出起始柱面号：

First cylinder (1-1305, default 1):

 

然后fdisk会告述我们可能的最大柱面号，在这里是1247,然后我们直接输入就行了：

Last cylinder or +size or +sizeM or +sizeK (1-1247, default 1247): 1247

 

然后看一下新的分区表：

Command (m for help): p

 

Disk /dev/sda: 10.7 GB, 10737418240 bytes

255 heads, 63 sectors/track, 1305 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

 

Device Boot Start End Blocks Id System

/dev/sda1 1 1247 10016496 83 Linux

/dev/sda2 1248 1305 465885 5 Extended

/dev/sda5 1248 1305 465853+ 82 Linux swap / Solaris

 

别忘了，之前的分区是启动分区，所以还需要做：

Command (m for help): a

Partition number (1-5): 1

 

最后写入：

Command (m for help): w

The partition table has been altered!

 

Calling ioctl() to re-read partition table.

 

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.

The kernel still uses the old table.

The new table will be used at the next reboot.

Syncing disks.

 

然后重新启动。还是启动到live-CD环境中（或者rescue模式），用su命令再次切换成root用户，然后运行：

fsck -n /dev/sda1

 

输出应该是这样的：

fsck 1.38 (30-Jun-2005)

e2fsck 1.38 (30-Jun-2005)

/dev/sda1: clean, 159036/765536 files, 1047239/1536000 blocks

 

接下来，在新的/dev/sda1上创建日志文件，转换回ext3文件系统：

tune2fs -j /dev/sda1

 

tune2fs 1.38 (30-Jun-2005)

Creating journal inode: done

This filesystem will be automatically checked every 30 mounts or

0 days, whichever comes first. Use tune2fs -c or -i to override.

 

好了，这下完成了。再次重启，启动到你原来的系统中，看看：

df

 

Filesystem 1K-blocks Used Available Use% Mounted on

/dev/sda1 9859036 4224032 5234348 45% /

varrun 95480 132 95348 1% /var/run

varlock 95480 0 95480 0% /var/lock

udev 10240 52 10188 1% /dev

devshm 95480 0 95480 0% /dev/shm

lrm 95480 17580 77900 19% /lib/modules/2.6.17-10-generic/volatile

 

df -B 4k

 

Filesystem 4K-blocks Used Available Use% Mounted on

/dev/sda1 2464759 1056008 1308587 45% /

varrun 23870 33 23837 1% /var/run

varlock 23870 0 23870 0% /var/lock

udev 2560 13 2547 1% /dev

devshm 23870 0 23870 0% /dev/shm

lrm 23870 4395 19475 19% /lib/modules/2.6.17-10-generic/volatile

 

df -h

 

Filesystem Size Used Avail Use% Mounted on

/dev/sda1 9.5G 4.1G 5.0G 45% /

varrun 94M 132K 94M 1% /var/run

varlock 94M 0 94M 0% /var/lock

udev 10M 52K 10M 1% /dev

devshm 94M 0 94M 0% /dev/shm

lrm 94M 18M 77M 19% /lib/modules/2.6.17-10-generic/volatile

 

fdisk -l

 

 

Disk /dev/sda: 10.7 GB, 10737418240 bytes

255 heads, 63 sectors/track, 1305 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

 

Device Boot Start End Blocks Id System

/dev/sda1 * 1 1247 10016496 83 Linux

/dev/sda2 1248 1305 465885 5 Extended

/dev/sda5 1248 1305 465853+ 82 Linux swap / Solaris

 

fdisk -s /dev/sda1

 

10016496

 

4、合并两个ext3分区：

 

在这个实例中，我的系统分区还是6GB左右的/dev/sda1，其后紧跟着/dev/sda3分区（大概4GB）。/dev/sda3挂载于/data目录，没有系统所需要的文件，只有用户数据。用df -h看，当前的分区就像这样：

df -h

 

Filesystem Size Used Avail Use% Mounted on

/dev/sda1 5.8G 4.1G 1.6G 73% /

varrun 94M 132K 94M 1% /var/run

varlock 94M 0 94M 0% /var/lock

udev 10M 56K 10M 1% /dev

devshm 94M 0 94M 0% /dev/shm

lrm 94M 18M 77M 19% /lib/modules/2.6.17-10-generic/volatile

/dev/sda3 3.5G 72M 3.3G 3% /data

 

为了合并两个分区，我们必须删除/dev/sda3分区，然后增大sda1分区，就像第三部分描述的那样。也就是说，所有/sda3上的数据全部都会消失。因此，如果你还需要它们的话，请首先备份数据，之后再拷贝到新的，并且更大的sda1上面。

现在，我们打开/etc/fstab，移除与/dev/sda3有关的行（如果存在的话）。新的，不包含/sda3分区信息的fstab应该是像这样的：

 

# /etc/fstab: static file system information.

#

#

proc /proc proc defaults 0 0

# /dev/sda1

UUID=566fd9e9-098f-4aae-9908-51efe171d8ba / ext3 defaults,errors=remount-ro 0 1

# /dev/sda5

UUID=82102b65-35db-469a-9532-03d619d8cffb none swap sw 0 0

/dev/hdc /media/cdrom0 udf,iso9660 user,noauto 0 0

/dev/ /media/floppy0 auto rw,user,noauto 0 0

 

然后，让我们umount /dev/sda3,用fdisk来删除它。首先umount /dev/sda3，然后fdisk /dev/sda（注意，这里是sda，不是sda3）：

The number of cylinders for this disk is set to 1305.

There is nothing wrong with that, but this is larger than 1024,

and could in certain setups cause problems with:

1) software that runs at boot time (e.g., old versions of LILO)

2) booting and partitioning software from other OSs

(e.g., DOS FDISK, OS/2 FDISK)

 

Type m to get a list of all commands:

 

Command (m for help): m

Command action

a toggle a bootable flag

b edit bsd disklabel

c toggle the dos compatibility flag

d delete a partition

l list known partition types

m print this menu

n add a new partition

o create a new empty DOS partition table

p print the partition table

q quit without saving changes

s create a new empty Sun disklabel

t change a partition's system id

u change display/entry units

v verify the partition table

w write table to disk and exit

x extra functionality (experts only)

 

现在，删除sda3：

Command (m for help): d

Partition number (1-5): 3

 

接下来，向硬盘写入新的分区表：

Command (m for help): w

The partition table has been altered!

 

Calling ioctl() to re-read partition table.

 

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.

The kernel still uses the old table.

The new table will be used at the next reboot.

Syncing disks.

 

最后，重新启动系统，进入Live-CD环境或者rescue系统，从这里开始，步骤和第三部分就完全一样的，从su到umount /dev/sda1，其后的步骤请自行参考第三部分。