Pods getting evicted due to The node was low on resource: ephemeral-storage

I see that pods are getting evicted due to ephemeral storage but when i looked at the nodes, has sufficient disk availability.

Filesystem     1K-blocks    Used Available Use% Mounted on
/dev/sda1        9983232 6479112   3487736  66% /

Following is the exact message from evicted pod

The node was low on resource: ephemeral-storage. Container nginx was using 228Ki, which exceeds its request of 0. Container istio-proxy was using 680Ki, which exceeds its request of 0.