You should always maintain backups of critical data! However, MSI follows best practices in protecting your data from loss or corruption, and in general your data is quite safe -- about as safe as any other data you might have stored in the cloud, and much safer than the hard drive in the computer on your desk.
Both the High Performance Primary Storage (Panasas) and the Second Tier Storage (Ceph) are protected by a RAID-like system so that data is not lost if some of the hard disks in our system fail. This approach protects against most hardware problems. However, this mechanism does not protect against errors in software or usage, such as accidental deletions.
In addition, group home directories on Primary Storage are protected by daily snapshots and tape backups. This ensures that if you accidentally overwrite or delete an important file it is possible to restore your files to an earlier state.
While these systems use best practice security methods, they are not approved to support legally protected datasets. Please contact email@example.com if you have legally protected data storage or analysis needs.