Storage down or offline (Pool used 90% capacity)

Hi everyone,
I am using portworx version 2.8.1.3. I had a problem when the pool used 90% of the capacity. The pool was then offline.
Please help me find the root cause.

Thanks,

thats the expected behavior. When pool hits 90%, the nodes go storage down . The quickest way to bring them back online is to reduce that free space threshold - pxctl cluster options update --free-space-threshold-gb XX