# Security For Linux Nodes

LLMS index: [llms.txt](/llms.txt)

---

<!-- overview -->

This page describes security considerations and best practices specific to the Linux operating system.

<!-- body -->

## Protection for Secret data on nodes

On Linux nodes, memory-backed volumes (such as [`secret`](/docs/concepts/configuration/secret/)
volume mounts, or [`emptyDir`](/docs/concepts/storage/volumes/#emptydir) with `medium: Memory`)
are implemented with a `tmpfs` filesystem.

If you have swap configured and use an older Linux kernel (or a current kernel and an unsupported configuration of Kubernetes),
**memory** backed volumes can have data written to persistent storage.

The Linux kernel officially supports the `noswap` option from version 6.3,
therefore it is recommended the used kernel version is 6.3 or later,
or supports the `noswap` option via a backport, if swap is enabled on the node.

Read [swap memory management](/docs/concepts/cluster-administration/swap-memory-management/#memory-backed-volumes)
for more info.