Feature introduction
In order to increase system performance, windows clients using SMB2 or SMB3 can use the SMB server-side copy (SSC) feature in PowerScale OneFS.
Windows clients can offload copy/move operations to the PowerScale cluster. In processing such a request, the network round-trip is avoided. Windows clients making use of server-side copy may experience performance improvements for file copy operations, because file data no longer needs to traverse the network. The server-side copy feature reads and writes files only on the PowerScale cluster, avoiding the network round-trip and duplication of file data.
Considerations
These are some key considerations that we recommend during the design and implementation:
- This feature only applies to file copy operations in which the source and destination file handles are open on the same share, and does not work for cross-share operations. When copying data across shares in a OneFS cluster, clients will pull the data from source share to local and write the data to destination share through network.
- It is recommended to upgrade OneFS cluster to a newer version if the cluster is running on the version prior to OneFS 8.0.0.3. For more information, see the article OneFS 8.0.x: Application unable to copy a file between shares.
- This feature is enabled by default on PowerScale cluster, and can only be disabled system-wide across all zones. You can disable the SMB server-side copy using the CLI command line on OneFS by running isi smb settings global modify --server-side-copy=no.
- Server-side copy is incompatible with the SMB continuous availability feature. If continuous availability is enabled for a share and the client opens a persistent file handle, server-side copy will be automatically disabled for that file.
- In OneFS versions 8.0.1.X and 8.1.0.X, a combination of having apple extensions enabled and SMB server-side copy being disabled will result in failures for copies in the Finder on macOS X. The workaround is to enable server-side copy on the cluster. Server-side copy is enabled by default. For more detailed information about this issue, see article OneFS 8.0.1.X & 8.1.0.X - If Apple extensions are enabled and SSC is disabled, Mac OS file copies via finder will fail.