I have set up 2 ubuntu instances in aws. How do I sync /usr/ubuntu in both the machines?
You can use
rsync command to sync two directories, e.g:
rsync -avzhe ssh -i yourkey.pem /usr/ubuntu root@ec2ip:/usr/ubuntu
This question has at least two answers.
If you need periodically sync your folders, you can use
If you need persistent sync and
/usr/ubuntu is distinguished disk partition, then you can use
DRBD. It's like Net-RAID. Describe and documentation about
DRBD - DRBD official site.
Set up one of the instances as an NFS server that exports the directory for the other instance to mount.