File Storage NAS (NAS) volumes give pods in ACK Serverless clusters shared, persistent access to a distributed file system — without managing storage capacity or performance manually.
What is NAS
NAS is an Alibaba Cloud distributed file system for compute nodes including Elastic Compute Service (ECS) instances, Elastic High-Performance Computing (E-HPC) clusters, and ACK clusters. It uses POSIX-based APIs and is compatible with native operating systems, so existing applications can mount NAS volumes without code changes.
| Property | Description |
|---|---|
| Shared access | Multiple pods can read from and write to the same file system simultaneously |
| Data consistency | Locks enforce mutual exclusion, preventing conflicting writes |
| Elastic capacity | Storage scales in and out automatically as files are added or removed |
| High reliability and performance | Suited for latency-sensitive workloads and applications that share data across nodes |
Storage types
NAS offers five file system types:
-
General-purpose Performance NAS file systems
-
General-purpose Premium NAS file systems
-
General-purpose Capacity NAS file systems
-
Standard Extreme NAS file systems
-
Advance Extreme NAS file systems
For a detailed comparison, see How do I select file systems?
Usage notes
Before mounting
-
After creating a mount target, wait until its Status changes to Available before using the volume.
-
Do not delete a mount target before unmounting the NAS file system — doing so may cause an operating system hang.
-
We recommend that you use the NFSv3 file sharing protocol.
Shared access behavior
-
NAS is a shared storage service. A persistent volume claim (PVC) that mounts a NAS file system can be shared by multiple pods.
Limits
-
General-purpose and Extreme NAS file systems have different limits on mounting scenarios, the number of file systems, and file sharing protocols. For details, see Limits.
Subpath PV behavior in ACK Serverless clusters
When you delete a persistent volume (PV) of the subpath type in an ACK Serverless cluster, the subdirectory is not deleted — even if reclaimPolicy is set to Delete. To remove the directory, manually mount the subdirectory and delete it.
Billing
For pricing details, see Billing of General-purpose NAS file systems.