在实际的运维过程中，会碰到/ 根目录下空间不足的时候，

可以考虑在加快硬盘，挂在一个目录下；
方法：在/ 根目录下建一个文件夹，把新加的硬盘mount 到这目录上。

 

step1；

linux 下添加第二块scsi 硬盘
如果是虚拟机的话，可以添加第二块虚拟硬盘
方法是：VM -- setting -- hardware --hard Disk --add 就可以添加一块scsi 硬盘。

 

step2: shutdown the vmware

在restart 就可以看到：
在虚拟的启动过程中就可以看到：

sda: sdb 的启动，就证明刚才的add disk success

原来没有add disk 的时候：

[root@sheng /]# fdisk -l

Disk /dev/sda: 42.9 GB, 42949672960 bytes
255 heads, 63 sectors/track, 5221 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1           6       48163+  83  Linux
/dev/sda2               7         515     4088542+  83  Linux
/dev/sda3             516         776     2096482+  82  Linux swap / Solaris
/dev/sda4             777        5221    35704462+   5  Extended
/dev/sda5             777        5221    35704431   83  Linux

 

增加后：需要重启：

 

[root@sheng ~]# fdisk -l

Disk /dev/sda: 42.9 GB, 42949672960 bytes
255 heads, 63 sectors/track, 5221 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1           6       48163+  83  Linux
/dev/sda2               7         515     4088542+  83  Linux
/dev/sda3             516         776     2096482+  82  Linux swap / Solaris
/dev/sda4             777        5221    35704462+   5  Extended
/dev/sda5             777        5221    35704431   83  Linux

Disk /dev/sdb: 2147 MB, 2147483648 bytes
255 heads, 63 sectors/track, 261 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdb doesn't contain a valid partition table
[root@sheng ~]#

 

下面要进行的是分区， add partition:

 

[root@sheng ~]# fdisk /dev/sdb
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel. Changes will remain in memory only,
until you decide to write them. After that, of course, the previous
content won't be recoverable.

Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)

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)

Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-261, default 1):
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-261, default 261):
Using default value 261

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.
[root@sheng ~]#

 

[root@sheng ~]# fdisk -l

Disk /dev/sda: 42.9 GB, 42949672960 bytes
255 heads, 63 sectors/track, 5221 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1           6       48163+  83  Linux
/dev/sda2               7         515     4088542+  83  Linux
/dev/sda3             516         776     2096482+  82  Linux swap / Solaris
/dev/sda4             777        5221    35704462+   5  Extended
/dev/sda5             777        5221    35704431   83  Linux

Disk /dev/sdb: 2147 MB, 2147483648 bytes
255 heads, 63 sectors/track, 261 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1         261     2096451   83  Linux

 

step3:

下面进行格式化：

把这个分区格式化 成 ext3 的格式，再创建文件系统
mkfs -t ext3 /dev/sdb1

 

step4:

创建mount point:

cd /

mkdir app

mount -t ext3 /dev/sdb1 /app

[root@sheng /]# mount -t ext3 /dev/sdb1 /app
[root@sheng /]# mount
/dev/sda2 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/sda5 on /home type ext3 (rw)
/dev/sda1 on /boot type ext3 (rw)
tmpfs on /dev/shm type tmpfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
none on /proc/fs/vmblock/mountPoint type vmblock (rw)
/dev/sdb1 on /app type ext3 (rw)

看到最后一行多了一行 : /dev/sdb1 被mount 上了。

[root@sheng /]# df -k
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/sda2              3960348   2420776   1335148  65% /
/dev/sda5             34586028    180280  32620528   1% /home
/dev/sda1                46633     10516     33709  24% /boot
tmpfs                   275812         0    275812   0% /dev/shm
/dev/sdb1              2063504     35880   1922804   2% /app

可以看到 /app 的used % 是2% ,这样就大大减小了 / 根目录的负担。达到目的。呵呵

哦，特别要注意的是：
最后要update /etc/fstab ,增加一行：

/dev/sdb1 /app ext3 defaults 1 2

不然下次启动的话，不会生效.