CloudLinux and CageFS
What CloudLinux and CageFS Are
CloudLinux CageFS is a security feature that gives each shared hosting account a restricted, virtual view of the file system, so the account can see only its own files and a small set of shared system files.
CloudLinux is a Linux distribution built for shared hosting servers. CageFS is one of its components, and it works together with resource controls that the same platform provides. Hosts use this combination to contain accounts on servers with many customers. It is one of several ways to isolate accounts, and not every host uses it.
How Resource Limits Work Alongside CageFS
CageFS handles visibility: what an account can see on disk. Resource limits handle consumption: how much an account can use. On CloudLinux, these limits are enforced through a mechanism called LVE, short for Lightweight Virtual Environment, which sets per-account caps on processor time, memory, input and output activity and the number of simultaneous processes.
Together they limit damage in two ways. A compromised account cannot wander through other customers' directories, and a runaway script or a hidden mining process cannot starve the rest of the server. An account that exceeds its limits is slowed down, while neighbouring sites keep running normally.
What These Tools Do Not Solve
Containment is not prevention. CageFS and resource limits do not patch vulnerable website software, and they do not protect a site whose owner uses a weak password. An attacker who compromises an account still controls that account's own files and data.
Hosts use these tools because they make shared servers more stable and reduce the reach of a single breach. The website owner still benefits from regular updates, strong credentials and monitoring, because containment limits the damage without removing the cause. Narrow access rights, explained in least privilege, add another layer.
Frequently asked questions
Does CageFS stop a website from being hacked?
No. CageFS limits what a compromised account can access on the server, but it does not stop the initial attack. Vulnerable code, weak passwords and leaked credentials can still give an attacker a foothold inside the account.
Do CloudLinux limits slow down a website?
Usually not for a well-optimised site that stays within its allowance. Limits matter during spikes, when an account tries to use more processor time or memory than it has been allocated. In that case, its requests may be slowed while other accounts remain unaffected.