Scenarios

If the capacity of system disk partitions is inconsistent with the actual system disk capacity after an ECS is created, you can add the empty partition to the root partition of the system disk.

This section describes how to add the empty partition to the non-end root partition online.

Procedure

In the following operations, the ECS that runs CentOS 6.5 64bit and has a 100 GB system disk is used as an example. The system disk has two partitions, /dev/xvda1: root and /dev/xvda2: swap, and the root partition is not the end partition.

Run the following command to view disk partitions:

parted -l /dev/xvda

[root@sluo-ecs-a611 ~]# parted -l /dev/xvda
Disk /dev/xvda: 107GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 

Number  Start   End     Size    Type     File system     Flags
 1      1049kB  41.0GB  40.9GB  primary  ext4            boot
 2      41.0GB  42.9GB  2000MB  primary  linux-swap(v1)

The first is the root partition, and the second is the swap partition.

View and edit the fstab partition table to delete the swap partition attaching information.

Run the following command to view the fstab partition table:

tail -n 3 /etc/fstab

[root@sluo-ecs-a611 ~]# tail -n 3 /etc/fstab 
#
UUID=7c4fce5d-f8f7-4ed6-8463-f2bd22d0ddea /                       ext4    defaults        1 1
UUID=5de3cf2c-30c6-4fb2-9e63-830439d4e674 swap                    swap    defaults        0 0

Run the following command to edit the fstab partition table and delete the swap partition attaching information.

vi /etc/fstab

tail -n 3 /etc/fstab

[root@sluo-ecs-a611 ~]# vi /etc/fstab 
[root@sluo-ecs-a611 ~]# tail -n 3 /etc/fstab 
#
UUID=7c4fce5d-f8f7-4ed6-8463-f2bd22d0ddea /                       ext4    defaults        1 1

Run the following command to disable the swap partition:
swapoff -a

Delete the swap partition.

Run the following command to view the partition:

parted /dev/xvda

[root@sluo-ecs-a611 ~]# parted /dev/xvda
GNU Parted 3.1
Using /dev/xvda
Welcome to GNU Parted! Type ´help´ to view a list of commands.
(parted) help                                                             
  align-check TYPE N                        check partition N for TYPE(min|opt) alignment
  help [COMMAND]                           print general help, or help on COMMAND
  mklabel,mktable LABEL-TYPE               create a new disklabel (partition table)
  mkpart PART-TYPE [FS-TYPE] START END     make a partition
  name NUMBER NAME                         name partition NUMBER as NAME
  print [devices|free|list,all|NUMBER]     display the partition table, available devices, free space, all found partitions, or a
        particular partition
  quit                                     exit program
  rescue START END                         rescue a lost partition near START and END
  rm NUMBER                                delete partition NUMBER
  select DEVICE                            choose the device to edit
  disk_set FLAG STATE                      change the FLAG on selected device
  disk_toggle [FLAG]                       toggle the state of FLAG on selected device
  set NUMBER FLAG STATE                    change the FLAG on partition NUMBER
  toggle [NUMBER [FLAG]]                   toggle the state of FLAG on partition NUMBER
  unit UNIT                                set the default unit to UNIT
  version                                  display the version number and copyright information of GNU Parted
(parted)

Press p.

Disk /dev/xvda: 107GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 

Number  Start   End     Size    Type     File system     Flags
 1      1049kB  41.0GB  40.9GB  primary  ext4            boot
 2      41.0GB  42.9GB  2000MB  primary  linux-swap(v1)

Run the following command to delete the partition:
rm 2
```
(parted) rm2   
```

Press p.

(parted) p 
Disk /dev/xvda: 107GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 

Number  Start   End     Size    Type     File system  Flags
 1      1049kB  41.0GB  40.9GB  primary  ext4         boot

Run the following command to edit the fstab partition table:

quit

(parted) quit                                                     
Information: You may need to update /etc/fstab.

Run the following command to view partition after the swap partition is deleted:

parted -l /dev/xvda

[root@sluo-ecs-a611 ~]# parted -l /dev/xvda
Disk /dev/xvda: 107GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 

Number  Start   End     Size    Type     File system  Flags
 1      1049kB  41.0GB  40.9GB  primary  ext4         boot

Run the following command to install the growpart tool:
This tool may be integrated in the cloud-utils-growpart/cloud-utils/cloud-initramfs-tools/cloud-init package. Run the yum install cloud-* command to ensure it is available.

yum install cloud-utils-growpart

Run the following command to expand the root partition (the first partition) using growpart:

growpart /dev/xvda 1

[root@sluo-ecs-a611 ~]# growpart /dev/xvda 1
CHANGED: partition=1 start=2048 old: size=79978496 end=79980544 new: size=209710462,end=209712510

Run the following command to verify that online capacity expansion is successful:

[root@sluo-ecs-a611 ~]# parted -l /dev/xvda
Disk /dev/xvda: 107GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 

Number  Start   End    Size   Type     File system  Flags
 1      1049kB  107GB  107GB  primary  ext4         boot

Run the following command to expand the capacity of the file system:

resize2fs -f $Partition name

Suppose the partition name is /dev/xvda1, run the following command:

[root@sluo-ecs-a611 ~]# resize2fs -f /dev/xvda1
resize2fs 1.42.9 (28-Dec-2013)
Filesystem at /dev/xvda1 is mounted on /; on-line resizing required
old_desc_blocks = 3, new_desc_blocks = 3
....
[root@sluo-ecs-a611 ~] # df -hT     //Check file system capacity expansion

How Can I Add the Empty Partition of an Expanded System Disk to the Non-end Root Partition Online?

Scenarios

Procedure