IBM Spectrum Scale / Storage Scale Container Native Storage Access: TENANT ISOLATION: programs running inside

Impact

TENANT ISOLATION: programs running inside a container can overcome the isolation mechanism of IBM Spectrum Scale Container Native Storage Access. Spectrum Scale (GPFS) is one of the two or three filesystems that actually keep up with large training clusters, and the container-native access layer is how Kubernetes-scheduled GPU jobs mount it. An isolation escape here means one tenant's pod reaching outside its intended storage boundary on shared cluster storage.

Who can reach it

A process inside a container that has Spectrum Scale container-native storage access — i.e. any tenant workload with a mounted volume.

What to do

Upgrade Container Native Storage Access past 5.1.6.0. This is a rolling upgrade of the storage-access DaemonSet/operator; pods remount as it rolls, so drain latency-sensitive jobs. No filesystem downtime, but plan for I/O stalls during the roll.

References