can the ClearML File server be configured to any kind of storage ? Example hdfs or even a database etc..

DeliciousBluewhale87 long story short, no 🙂 the file server, will just store/retrieve/delete files from a local/mounted folder

Is there any ways , we can scale this file server when our data volume explodes. Maybe it wouldnt be an issue in the K8s environment anyways. Or can it also be configured such that all data is stored in the hdfs (which helps with scalablity).I would suggest to use object storage for that, basically from the user perspective this is transparent, you can configure your client with (s3/gs/azure are supported):
files_server: " "https://github.com/allegroai/clearml/blob/470aa8c52de34b3e6b9ff543e51d29cc285f0b18/docs/clearml.conf#L10

Is there any security to protect this data in this storage ?

In the open-source version, there is not authentication check to serve specific files, on the paid tiers there is full security/authentication on top of the files server