First off, let me say I am a software guy, not an admin, so please forgive me if I get terminology wrong.
I'm writing software that runs on a Centos 6.4 VM on Openstack Grizzly, running KVM. It has a 2TB SSD ephemeral drive and is configured with vertio drivers.
The program writes 6 files, 40GB each. As soon as it exits, another program moves those files to another directory on the same volume and processes them.
What we are seeing is that the files are corrupt after moving them. Either of the following will prevent the corruption:
- sync and wait 5 minutes before moving the files, OR
- reformat the filesystem to xfs
As far as I know, any write caching should be completely transparent to all user-mode programs. Before I call xfs a "fix", I'd like to know the root cause. Any idea?