Cloud Parallel File Storage:Limits

File system

Operating systems

Filesets

• Fileset specification limits

  • A CPFS file system supports a maximum of 10 filesets.

  • The maximum directory depth to which a fileset can be linked within a CPFS file system is 8.

  • The maximum number of files or directories in a fileset is 1 million.

  • Nested filesets are not supported.

Data flows

• Data flow specification limits

  • A CPFS file system supports a maximum of 10 data flows.

  • A single data flow can have a maximum of five auto-updating directories.

  • A fileset in a CPFS file system can be linked to only one Object Storage Service (OSS) bucket.

  • Data flow task records are retained for a maximum of 90 days.

  • Data flow task reports are saved in the CPFS file system and consume storage space. A maximum of 1 million reports can be saved.

  • CPFS file systems do not support creating data flows with OSS buckets in other regions.

• Limits of dataflows on file systems
  • You cannot rename a non-empty directory in a fileset that is associated with a dataflow. Otherwise, the error message Permission Denied or an error message indicating that the directory is not empty is returned.
  • Archive or Cold Archive objects in OSS do not support dataflows.
  • Proceed with caution when you use special characters in the names of directories and files. The following characters can be contained: letters, digits, exclamation points (!), hyphens (-), underscores (_), periods (.), asterisks (*), and parentheses ().
  • The path can be 1 to 1023 characters in length. A path that is too long is not supported.
• Limits of dataflows on export
  • Hard links and symbolic links cannot be exported to an OSS bucket.
  • Empty directories cannot exported to an OSS bucket.
  • CHANGTIME attributes cannot be exported to an OSS bucket.
  • The zero entries in sparase data are specified before they are exported to an OSS bucket.

Protocol services

• Protocol service specification limits

  Item	Threshold	Description
  Maximum number of protocol services that can be created for a CPFS file system	1	You can create only one protocol service for a CPFS file system.
  Maximum number of virtual private clouds (VPCs) to which export directories can be published by using a protocol service	2	You can use a protocol service to publish export directories to up to two VPCs.
  Maximum number of export directories that can be created by using a protocol service	10	You can use a protocol service to create an export directory for up to 10 filesets or directories.
  Maximum number of compute nodes that can be mounted by using a protocol service	10,000	You can mount up to 10,000 compute nodes by using a protocol service.
  Maximum number of files that can be opened by using a protocol service at the same time	150,000	You can use a protocol service to open up to 150,000 files at the same time.

• Other limits

  • A protocol service allows multiple clients to read and write files in a unified namespace in a shared manner. However, in scenarios in which multiple processes or clients concurrently write the same file such as a log file, the processes or clients maintain their own context information such as file descriptors and write locations, but the NFSv3 protocol itself does not support Atomic Append. In this case, write anomalies such as overwrite, crossover, and serialization may occur.

  • Network Lock Manager (NLM) is not supported.

  • NFSv4.x is not supported.