Business Scenarios

After an ECS is created, you need to manually initialize EVSs attached to the ECS before using them. If multiple ECSs are added to the AS group, you must initialize the EVSs on each ECS, which takes a while.

This section describes how to configure a script to enable automatic initialization of EVSs, including disk partitioning and attachment of specified directories. The script can only be used to initialize one EVS. This section uses CentOS 6.6 as an example. For how to configure automatic initialization of EVSs on other OSs, see the relevant OS documentation.

Operation Steps

Log in to the ECS as user root . Run the following command to switch to the directory where the script will be stored.

cd /script directory

For example:

cd /hom

Execute the following command to create and edit the script.

vi script name

For example:

vi fdisk_mount.sh

The following script is used as an example to show how to implement automatic initialization of one data disk on the ECS:

#!/bin/bash
bash_scripts_name=fdisk_mount.sh ini_path=/home/fdisk.ini
disk=
size=
mount=
partition=
function get_disk_from_ini()
{
disk=cat $ini_path\|grep disk\| awk -F '=' '{print $2}'
if [**disk = "" ]
then
echo "disk is null in file,exit"
exit
fi
result=fdisk -l**disk | grep**disk
if [**result = 1 ]
then
echo "disk path is not exist in linux,exit"
exit
fi
}
function get_size()
{
size=cat $ini_path\| grep size\|awk -F '=' '{print $2}'
if [**size = "" ]
then
echo "size is null,exit"
exit
fi
}
function make_fs_mount()
{
mkfs.ext4 -T largefile**partition
if [**? -ne 0 ]
then
echo "mkfs disk failed,exit"
exit
fi
dir=cat**ini_path|grep mount |awk -F '=' '{print $2}'
if [ dir = "" ] then echo "mount dir is null in file,exit" exit fi if [ ! -d dir ]
then
mkdir -p dir fi mount partition dir if [ ? -ne 0 ]
then
echo "mount disk failed,exit"
exit
fi
echo "partition dir ext3 defaults 0 0" >> /etc/fstab
}
function remove_rc()
{
cat /etc/rc.local | grep bash_scripts_name if [ ? ne 0 ]
then
sed -i '/'bash_scripts_name'/d' /etc/rc.local fi } ################## start #########################1. Check whether the configuration file exists if [ ! -f ini_path ]
then
echo "ini file not exist,exit"
exit
fi

##2. Get the device path for the specified disk from the configuration file
get_disk_from_ini

##3. Get the size of the size partition from the configuration file
get_size

##4. Partition the disk.
fdisk disk <<EOF n p 1 1 size
w
EOF
partition=fdisk -l $disk 2>/dev/null| grep "^/dev/[xsh].*d" | awk '{print $1}'

##5. Format the partition and attach the partition to the specified directory
make_fs_mount

##6. Change startup items to prevent re-execution of the scripts
remove_rc

echo 'SUCESS'

Press Esc , enter :wq , and press Enter to save the changes and exit.

Run the following command to create the configuration file:

Vi fdisk.ini

The drive letter, size, and attach directory of the EVS are configured in the configuration file. You can change the settings based on the following displayed information.

disk=/dev/xdev
size=+100G
mount=/opt/test

Press Esc , enter :wq , and press Enter to save the changes and exit.

Execute the following command to open the configuration file "rc.local".

Vi /etc/rc.local

Press i to add the following content to rc.local :

/home/fdisk_mount.sh

After rc.local is configured, the EVS initialization script will be automatically executed when the ECS starts.

Press Esc , enter :wq , and press Enter to save the changes and exit.

Create a private image using an ECS.

When you specify the AS configuration information, select the private image created in the preceding step and select an EVS.

When you configure the AS group, select the AS configuration created in the preceding step.

Action Results

After the AS group is created, EVSs of new ECSs added to this AS group in scaling actions will be automatically initialized according to the configuration in the private image.

Auto Scaling

Initializing an ECS Data Disk