OpenAFS logo

May 24-28, 2010

University of Illinois at Urbana-Champaign logo

Wednesday 26 May 11:00am

Location: 1320 Digital Computer Lab

Speaker: Kim Kimball

Title: Volinfo on steroids: Rapidly enumerate a volume's directories, files, mount points, ACLs ...


Though it is possible to scan a volume by mounting it and iterating down the tree, this loads the fileserver process, runs afoul of embedded mount points to other volumes, requires credentials, and to add insult to injury it's slow.

A much more efficient way to scan a volume for a list of files, directories, mount points, stat information (think "ls -l"), and Access Control List information is to process the volume directly on the relevant vice partition.

The "volinfo" tool provided with the OpenAFS distribution provides some information about a specified volume, but not all of it.

In an effort to make OpenAFS an ITAR-compliant file system, I developed a tool that processes volume headers and extracts directory structure, directory contents, mode bits, ACLs, and other goodies.

The tool has been run nightly for more than a year.

I'll describe the solution and the implementation and provide some example output, as well as benchmarking information.