最近將阿里雲伺服器的系統盤擴容了2T,但是過了很長時間，我的系統依舊是原來的1T，磁碟確實已經擴大到2T，於是搜尋了一下看看什麼原因導致，其實是我們的系統盤原本已經做了分割槽，雖然系統盤擴容，但是我們的分割槽沒有做改動，所以我們應該對系統盤的分割槽.

一、安裝growpart

[root@iZuf681ncvagioevqx84nuZ all-sql]# yum install -y cloud-utils-growpart gdisk

二、檢視磁碟實際大小

[root@iZuf681ncvagioevqx84nuZ ~]# fdisk  -l

Disk /dev/vda: 214.7 GB, 214748364800 bytes, 419430400 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x0008d207

   Device Boot      Start         End      Blocks   Id  System
/dev/vda1   *        2048   419430366   209714159+  83  Linux

Disk /dev/vdb: 2147.5 GB, 2147483648000 bytes, 4194304000 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x00d2a2f3

   Device Boot      Start         End      Blocks   Id  System
/dev/vdb1            2048  2097151999  1048574976   83  Linux

Disk /dev/mapper/docker-253:1-263986-pool: 107.4 GB, 107374182400 bytes, 209715200 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 65536 bytes / 65536 bytes
 

三、檢視磁碟分配大小

[root@iZuf681ncvagioevqx84nuZ ~]# df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/vda1       197G  185G  3.1G  99% /
devtmpfs         16G     0   16G   0% /dev
tmpfs            16G     0   16G   0% /dev/shm
tmpfs            16G  792K   16G   1% /run
tmpfs            16G     0   16G   0% /sys/fs/cgroup
/dev/vdb1       985G  870G   65G  94% /data
tmpfs           3.2G     0  3.2G   0% /run/user/0
 

四、自適應分割槽擴容

#表示為系統盤的第一個分割槽（/dev/vdb1）擴容。
[root@iZuf681ncvagioevqx84nuZ ~]# growpart /dev/vdb 1
CHANGED: partition=1 start=2048 old: size=2097149952 end=2097152000 new: size=4194301919 end=4194303967

五、重設分割槽大小

[root@iZuf681ncvagioevqx84nuZ ~]# resize2fs /dev/vdb1
resize2fs 1.42.9 (28-Dec-2013)
Filesystem at /dev/vdb1 is mounted on /data; on-line resizing required
old_desc_blocks = 125, new_desc_blocks = 250
The filesystem on /dev/vdb1 is now 524287739 blocks long.
 

六、再次檢視磁碟分割槽大小

[root@iZuf681ncvagioevqx84nuZ ~]# df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/vda1       197G  187G  983M 100% /
devtmpfs         16G     0   16G   0% /dev
tmpfs            16G     0   16G   0% /dev/shm
tmpfs            16G  784K   16G   1% /run
tmpfs            16G     0   16G   0% /sys/fs/cgroup
/dev/vdb1       2.0T  870G 1009G  47% /data
tmpfs           3.2G     0  3.2G   0% /run/user/0

可以看到分割槽（/dev/vdb1）容量已經是2T，表示已經成功擴容。

在整個過程中，無需重啟伺服器，所以不會影響到伺服器上正在執行的服務。