Create RAID on Amazon EC2 EBS volumes

If you use Amazon AWS cloud services you definitively want to utilize software raid for IO intensive stuff such as database data directories and the like.

Here's how you create it:

• Create some EBS volumes within management console or
• sudo mdadm --create -f /dev/md0 --chunk=256 --level 10 --raid-devices 4 /dev/sdf /dev/sdg /dev/sdh /dev/sdi
• Create a fs on /dev/md0 using mkfs*-tools
• As soon as this is running, you should do that:
  sudo mdadm --detail --scan >> /etc/mdadm/mdadm.conf

Make sure the last line in /etc/mdadm/mdadm.conf looks like that

CopyARRAY /dev/md0 level=raid0 num-devices=4 metadata=00.90 UUID=1234567893:abcdef:123