You will get a usable image of your database files for disaster recovery purposes.
There is no guarantee they will be consistent on Linux. The open files backups on Linux only delivers file system consistency. Any application, like MySQL for example, likely has changes to data in resident memory that have not yet been written to disk. The file system and backup driver (kernel module) do not know about them and can not back them up.
The situation is different on our soon to be released Windows product. On Windows, we have the Volume Shadow Copy API. This API allows software vendors to be notified of a Backup operation and sync these modifications in memory to disk. MySQL on Windows does not integrate with Volume Shadow Copy, but SQL Server does.