This is one you can file under easy and obvious but since I have a memory like a sieve I am going to write about it. There are times when I set up EBS volumes and think to myself, “I’ll never need anymore than nGB, ever!”, only to find out some months down the road my estimates were woefully short for the growth trend. Turns out resizing is pretty easy and can be accomplished in a matter of minutes. For this example, I’m going to resize a single EBS volume using XFS and where a MySQL database hangs out doing its thing. I am going to attach it to a separate block device than the original volume so that we can quickly revert back if we find the apocalypse happening ahead of schedule.

1. Put up a maintenance page or just halt activity to the DB so that your life is slightly more elegant.
2. Stop MySQL
3. Make a snapshot of the original EBS volume
4. Create a new volume from that snapshot specifying the size you want and make sure that it is in the same availability zone as the instance you want to attach it to
5. Attach the new EBS volume to your instance on a different block device (if the original is on /dev/sdh then attach the new one to /dev/sdi)
6. Edit /etc/fstab to reflect the new changes:

   #/dev/sdh /vol xfs noatime 0 0
/dev/sdi /vol xfs noatime 0 0

7. Mount the drive
8. Resize it with “xfs_growfs -d /vol”
9. Start MySQL and let it run its checks
10. Take down the maintenance pages and sit back with a sense of smug self-satisfaction

Like I said, super easy. However, this is for a single EBS volume I haven’t really played around with resizing or generally manipulating RAID sets so that is a post for another day.