As discussed last year: Current Linux copy tools have various problems compared to other platforms - small I/O sizes (and most don't allow it to be configured), lack of parallel I/O for multi-file copies, inability to reduce metadata updates by setting file size first, lack of cross mount (to the same file system) copy optimizations, limited ability to handle the wide variety of server side copy (and copy offload) mechanisms and error handling problems. And copy tools rely less on the kernel file system (vs. code in the user space tool) in Linux than would be expected, in order to determine which optimizations to use. But some progress has been made since last year's summit, with new copy tools being released and improvements to some of the kernel file systems, and also some additional feedback on lwn and on the mailing lists. In addition these discussions have prompted additional feedback on how to improve file backup/restore scenarios (e.g. to mounts to the cloud from local Linux systems) which require preserving more timestamps, ACLs and metadata, and preserving them efficiently. Let's continue our discussions from last year, and see how we can move forward on improving the performance and function of Linux fs (including the VFS and user space tools) for various backup, restore and copy scenarios operations.
