As part of my ongoing work I’ve been measuring the size and depth of mozilla-central to extrapolate future repository size for scaling purposes. Part of this was figuring out some details such as average file size, distribution of types of files, and on-disk working copy size versus repository size.

When I posted a graph comparing the size of the mozilla-central repository by Firefox version my colleague gszorc was quick to point out that the 4k blocksize of the filesystem meant that the on-disk size of a working copy might not accurately reflect the true size of the repository. I considered this and compared the working copy size (with blocksize =1) to the typical 4k blocksize. This is the result.