线上服务器对根分区进行磁盘扩容

date：2016-04-07

今天领导让我对一台服务器的根分区做扩容，记下来做笔记使用。

[root@logstashsvr ~]# df -hT
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/vg_logstashsvr-LogVol00 ext4 290G 207G 69G 76% /
tmpfs tmpfs 2.9G 0 2.9G 0% /dev/shm
/dev/sda1 ext4 194M 28M 156M 16% /boot

通过fdisk -l 查看插了一块/dev/sdb 的硬盘进来接下来

对第二块硬盘sdb进行分区

[root@logstashsvr ~]# fdisk /dev/sdb
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0xf47f4312.
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)

WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').

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): p

Disk /dev/sdb: 1073.7 GB, 1073741824000 bytes
255 heads, 63 sectors/track, 130541 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xf47f4312

Device Boot Start End Blocks Id System

Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-130541, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-130541, default 130541):
Using default value 130541
Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

说明：上面操作对sdb硬盘进行了分区操作，设为sdb1分区了（当然上面建立的主分区可以为1-4中的任意一个，我这里选择的1）。

接下来就是：

使用工具partprobe让kernel读取分区信息

partprobe

使用fdisk工具只是将分区信息写到磁盘，如果需要mkfs磁盘分区则需要重启系统，

而使用partprobe则可以使kernel重新读取分区 信息，从而避免重启系统。

[root@logstashsvr ~]# partprobe /dev/sdb
-bash: partprobe: command not found
提示我们没有找到，那我们就安装。

[root@logstashsvr ~]# yum -y install parted
然后再执行

[root@logstashsvr ~]# partprobe /dev/sdb

对新建立的分区进行格式化，这个过程时间比较长。

[root@logstashsvr ~]# mkfs.ext4 /dev/sd
sda sda1 sda2 sdb sdb1
[root@logstashsvr ~]# mkfs.ext4 /dev/sdb1
mke2fs 1.41.12 (17-May-2010)
文件系统标签=
操作系统:Linux
块大小=4096 (log=2)
分块大小=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
65536000 inodes, 262142637 blocks
13107131 blocks (5.00%) reserved for the super user
第一个数据块=0
Maximum filesystem blocks=4294967296
8000 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
102400000, 214990848

正在写入inode表: 完成
Creating journal (32768 blocks): 完成
Writing superblocks and filesystem accounting information: 完成

This filesystem will be automatically checked every 29 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override

接下来我们可以查看一下vgdisplay查看卷祖的闲置空间是多少，方便下面的逻辑卷扩展，这里我忘了看了，就直接+100FREE全部用掉了

[root@logstashsvr ~]# lvextend -l +100%FREE /dev/vg_logstashsvr/LogVol00
Extending logical volume LogVol00 to 1.26 TiB
Logical volume LogVol00 successfully resized
[root@logstashsvr ~]# resize2fs /dev/vg_logstashsvr/LogVol00

这一步我等了一两个小时。以为出什么问题了呢。

resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/vg_logstashsvr/LogVol00 is mounted on /; on-line resizing required
old desc_blocks = 19, new_desc_blocks = 81
Performing an on-line resize of /dev/vg_logstashsvr/LogVol00 to 339197952 (4k) blocks.
The filesystem on /dev/vg_logstashsvr/LogVol00 is now 339197952 blocks long.

[root@logstashsvr ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_logstashsvr-LogVol00 1.3T 207G 1003G 18% /
tmpfs 2.9G 0 2.9G 0% /dev/shm
/dev/sda1 194M 28M 156M 16% /boot
大功告成!!!!!