You need a POSIX filesystem shared by horizontally scaled instances that can sustain up to 100 MB/s of writes. Which storage option should you use?

Cloud Filestore provides fully managed Network Attached Storage (NAS) for Compute Engine and GKE instances. It offers a POSIX-compliant filesystem, which is essential for shared access across multiple instances requiring file-level locking and consistency. Filestore instances can easily sustain 100 MB/s of writes, especially with higher service tiers. Persistent Disk (both zonal and regional) is block storage, not a shared filesystem, and cannot be simultaneously attached to multiple instances in a read/write manner. Cloud Storage is object storage; while it can be mounted via gcsfuse, gcsfuse is not fully POSIX-compliant and may not offer the performance or consistency guarantees needed for demanding shared filesystem workloads.