So I’ve been working on a system where the MySQL instance on EC2 sporadically locks up (mysqld is zombied) during a snapshot process =)

Essentially the EC2 snapshot is triggered like this:

system("xfs_freeze -f /vol")                        and die;
system("ec2-create-snapshot $vol -K $key -C $crt ") and die;
system("xfs_freeze -u /vol")                        and die;

This method is based on advice from here

Notice I [...]