Blockchain-based file storage services are designed with fault tolerance and redundancy in mind. When you upload a file, it is encrypted, split into shards, and distributed across multiple nodes in the network. If a node goes offline, the system can still retrieve your data from other nodes storing the remaining shards. This process ensures that your files remain accessible even in the event of node failures or network disruptions. Additionally, many platforms have built-in mechanisms to monitor node availability and redistribute file shards as needed to maintain data integrity and availability.