Scale and Performance of AFSv2

With the new protocol in place, AFSv2 was measured and found to be much more scalable than the original version. Indeed, each server could support about 50 clients (instead of just 20). A further benefit was that client-side performance often came quite close to a local performance because in the common case, all file accesses were local; file reads usually went to the local disk cache (and potentially, local memory). Only when a client created a new file or wrote to an existing one was there a need to send a Store message to the server and thus update the file with new contents.

AFS vs. NFS

Let us also gain some perspective on AFS performance by comparing common file-system access scenarios with NFS. The figure below shows the results of our qualitative comparison.