docs(srv): add tb on tmpfs-related oom issues

Author: SamyOubouaziz

pages/serverless-containers/reference-content/containers-sandbox.mdx

@@ -25,4 +25,27 @@ Sandbox v1 is known to experience clock drift over time. A difference of approxi
 ## Sandbox v2
 
 Sandbox v2 is a modern isolation environment that relies on [gVisor](https://gvisor.dev/). This option offers faster [cold starts](/serverless-containers/concepts/#cold-start), but only implements a selection of Linux syscalls.
+
 Refer to the [official gVisor documentation](https://gvisor.dev/docs/user_guide/compatibility/linux/amd64/) for a comprehensive list of supported syscalls.
+
+## Sandbox special directories
+
+In sandbox v1 and v2, some directories are mounted as `tmpfs` for temporary in-memory storage:
+
+| Sandbox v1 |Sandbox v2 |
+|---|---|
+| /dev (max size: 65 536 KB) | /dev (no max size)|
+| | /tmp (no max size) |
+
+In Sandbox v1, the size is limited, and its impact on memory usage is negligible.
+
+In Sandbox v2, directories such as `/tmp` and `/dev` are stored in memory. This means that any data written to `/tmp` consumes RAM directly. For example, writing a 100 MB file to `/tmp` will increase the container’s memory usage by the same amount.
+
+Since this usage counts toward the container’s memory limit, excessive writes to `/tmp` can lead to out-of-memory (OOM) errors, potentially triggering a container restart.
+
+To avoid this, we recommend being cautious when writing temporary files in `/tmp`, especially in long-running or high-throughput workloads.
+
+Applications that rely heavily on temporary file storage should either:
+- Use alternative storage paths within your container
+- Increase the container’s memory allocation to accommodate for temporary file usage
+- Use ephemeral storage

pages/serverless-containers/troubleshooting/container-oom.mdx

@@ -0,0 +1,27 @@
+---
+title: My container runs out of memory (OOM)
+description: Troubleshoot issues encountered with Scaleway Serverless Containers running out of memory and restarting.
+tags: serverless containers troubleshooting issue error memory ram oom restart crash freeze bsod
+dates:
+  validation: 2025-12-03
+  posted: 2025-12-03
+---
+
+## Problem
+
+My container runs out of memory (OOM) and crashes or restarts.
+
+## Possible cause
+	
+In sandbox v1 and v2, some directories are mounted as `tmpfs` for temporary in-memory storage. In Sandbox v2, directories such as `/tmp` and `/dev` are stored in memory.
+
+Excessive writes to `/tmp` can fill up the provisioned memory, leading to out-of-memory (OOM) errors, potentially triggering a container restart.
+
+## Solutions
+
+- Avoid writing temporary files in `/tmp`.
+- Use alternative storage paths within your container
+- Increase the container’s memory allocation to accommodate for temporary file usage
+- Use ephemeral storage
+
+Refer to the [dedicated documentation](/serverless-containers/reference-content/containers-sandbox/) for more information on Sandboxes.

pages/serverless-containers/troubleshooting/index.mdx

@@ -71,4 +71,5 @@ productIcon: ContainersProductIcon
   - [I cannot access my container](/serverless-containers/troubleshooting/cannot-access-container/)
   - [No data show up on Grafana dashboards](/serverless-containers/troubleshooting/no-data-grafana-dashboards/)
   - [I get errors when using HTTP/1.0](/serverless-containers/troubleshooting/http1-errors/)
+  - [My container runs out of memory](/serverless-containers/troubleshooting/container-oom/)
 </LinksList>