Definition
A RAM-only server, also called a diskless server, runs its entire operating system and configuration from RAM rather than from a hard disk. The OS is loaded into memory at boot from a read-only network source, and no data is ever written to persistent storage. When the server reboots — voluntarily or because the power is cut — the entire state is wiped. There is no log file, no cache, no temporary database that survives the restart.
Why It Matters for VPNs
A no-logs policy is a promise; a RAM-only architecture is a structural guarantee. Even if law enforcement physically seizes the server, all that exists on it is the running state at that instant — no historical records, because the disk on which they would have been written does not exist. This raises the bar from 'we claim not to log' to 'we cannot retain logs'. ExpressVPN's TrustedServer, Surfshark's Nexus, NordVPN's RAM servers, and ProtonVPN's infrastructure are all examples of this approach.
Limits
RAM-only does not protect against real-time interception. If a server is compromised or compelled to start logging in memory, the attacker or authority sees traffic from that point forward. It also does not eliminate the trust requirement in the provider — the provider must actually configure the servers correctly. Independent audits that verify the architecture (rather than just reading the privacy policy) are the appropriate evidence.