I am using server 3.2.12. FsyncLock() commands appear to corrupt the disk data such that a snapshot taken at this time does not work. Once the mongod process starts again on the snapshot disk it appears to ignore all the existing data files - none of the previous databases are shown.

I am able to reproduce the issue consistently. Here are my steps
1. Start with a sample data
2. db.fsyncLock()
3. Snapshot the disk
4. db.fsyncUnLock()

I have attached a .zip of mongodb data folder from my tests. Here is the login credential for initial data
mongo -u admin -p "K2NU3rNn0YBHX3p1" 127.0.0.1/admin

1. initialdata.zip - initial data
2. snapdata.zip - This is the data from the snapshot
3. dataaftersnaprestart - This is the data after restarting mongod on the snapshot