This topic describes the limits of CPFS for Lingjun file systems.
File system limits
Limit | Threshold | Notes |
Mount targets per file system | 1 | One VPC mount target per file system. |
Subdirectory mounting | Supported | You can mount a subdirectory. |
Maximum capacity | 1 PiB | For larger (up to 20 PiB), submit a ticket. |
Maximum files or directories | 10 billion | Grows with capacity. |
Max nodes via VSC | 4,000 | Per file system. |
Max path length | 4,096 bytes | Linux VFS limit. |
Max file name length | 255 bytes | |
Max ECS instances per VPC mount target | 6,000 | 500 ECS per 300 TiB. For more, submit a ticket. |
Mounting
CPFS for Lingjun can only be mounted from Platform for AI (PAI) (Lingjun resources, PAI general computing, or PAI Lingjun single-tenant) and Container Compute Service (ACS) (high-performance networking GPU workloads). ECS instances are not supported.
Supported OS
OS | Distribution | Kernel version |
Alibaba Cloud Linux | Alibaba Cloud Linux 3 | 5.10.134-13 or later |
Ubuntu | Ubuntu 24.04 | 6.8.0-79 or later |
Protocol
Only POSIX is supported.
Scaling
Scale-out only. Step: 10,240 GiB. Max: 1 PiB. For 20 PiB, submit a ticket.
Dataflow
Dataflow
Same account: CPFS for Lingjun 2.4.0 and later. Cross-account: 2.6.0 and later.
Max 10 dataflow per file system.
One file path maps to one OSS bucket.
Source and destination must be in the same region.
Path and filename restrictions
Supported | Not supported |
Letters, digits, |
|
Do not rename non-empty directories in dataflow paths. Avoid special characters.
Dataflow tasks
Supported in CPFS for Lingjun 2.6.0 and later. OpenAPI only.
Max 4 batch tasks per dataflow No limit on dataflow tasks.
Import limits
Symlinks become regular files. Symlink info is lost.
Only latest object version is copied from OSS.
No file or directory names longer than 255 bytes.
Export limits
Symlinks become empty OSS objects. Targets are not synced.
Hard links become regular files.
Socket, Device, and Pipe files become empty objects.
Directory paths > 1023 chars not supported.
Fileset
Fileset is whitelist-only. Submit a ticket to request access.
Fileset limits
Limit | Threshold |
CPFS version | V2.7.0 and later |
Filesets per file system | 500 (default). Up to 3,000 via ticket. |
Files/directories per fileset | 10 billion |
Nested filesets | Not supported |
Hard links across filesets | Not supported |
Fileset path rules
Path must start and end with
/.Path must be new. Cannot modify existing paths.
Parent directory must exist for multi-layer paths.
Max depth: 8 layers (root = 0). Max path length: 990 chars.
Single-layer name: max 255 chars. Allowed: letters, digits,
_,.,-.
Fileset deletion
Delete via console or API. Storage is reclaimed after 24 hours. To free immediately, clear data first, then delete. Deleted data cannot be recovered.
Fileset quota
Limit | Description |
Version | CPFS Compute Edition 2.7.0 and later |
Quotas per path | 1 |
Capacity quota | Min 10 GiB, step 1 GiB |
File count quota | Min 10,000, step 1, max 10 billion |
When quota reached | No new writes |
Statistics latency | ~15 minutes |
Modify quota | New value must exceed used capacity or file count |