Question

Amazon provides instance store for EC2 instances. If you use your own AMI, these are not formatted or mounted automatically for you. You need to manually format and mount them.

The available devices are listed here and vary based on type of instance. For example an m1.small will have different available instance store devices than c1.xlarge.

I’m looking for a script which

1. Detects what the instance type is. Perhaps by using
   curl -s http://169.254.169.254/latest/meta-data/instance-type
2. Formats and mounts all devices which are available for that instance type but have not yet been formatted/mounted.

Possible? Done it? Have it?

Answer 1

So, here is what I built for this.

#!/bin/bash

# This script formats and mounts all available Instance Store devices

##### Variables
devices=( )

##### Functions

function add_device
{
    devices=( "${devices[@]}" $1 )
}

function check_device
{
    if [ -e /dev/$1 ]; then
        add_device $1
    fi
}

function check_devices
{
    check_device sda2
    check_device sda3
    check_device sdb
    check_device sdc
    check_device sdd
    check_device sde
}

function print_devices
{
    for device in "${devices[@]}"
    do
        echo Found device $device
    done
}

function do_mount
{
    echo Mounting device $1 on $2
fdisk $1 << EOF
n
p
1



w
EOF
# format!
mkfs -t xfs -f $1

mkdir $2
mount $1 $2

echo "$1   $2      xfs     defaults          0 0" >> /etc/fstab

}

function mount_devices
{
    for (( i = 0 ; i < ${#devices[@]} ; i++ ))
    do
        mountTarget=/mnt
        if [ $i -gt 0 ]; then
            mountTarget=/mnt$(($i+1))
        fi
        do_mount /dev/${devices[$i]} $mountTarget
    done
}


##### Main

check_devices
print_devices
mount_devices