Hi Paul, > It seems that you looked at the performance of 1 client with > 1 server? Are your figures for a single access to a server?
I know that AFS is better performing then NFS if you count many clients especially if you have a read bias on these clients. We are using AFS because of that since a year. After all we had the NFS thing for over 10 years ... it was real pain. So, please note: you are completely right -- but for compiler research as we do "make clean; make; make test ... minor editing ... do it all again" is a major task. So we are really suffering from a factor 10 to 100 slower delete performance!!! This is affecting single users, true, but it is a not neglectable cost and acceptance problem! > > Since AFS caches data, it is likely that multiple access to > the data will show AFS has better performance. > > You could also try using an AFS RAM cache to see how that > improves AFS access over say 10 accesses to same data. > > What would be more interesting than a > single-server:single-client comparison is to look at how > performance varies as the number of clients increases. > > Such as study was done a few years ago using the Andrew > Benchmark [0]. A graph [1] of the results is attached below. > > What is interesting about the graph is that AFS is clearly > shown to have much better scalability than NFS: as the number > of clients rises, AFS outshines NFS. > > From this data, it is clear that AFS has better scalability than NFS. > > The other thing to remember is that, when comparing AFS with > NFS, you are not really comparing like for like [2]. > > For example: AFS has features and capabilities not available > in NFS. In AFS: > > + You can move data between fileservers with little > or no impact on users accessing that data. > > + You can replicate data across several servers so that > AFS clients will automagically switch to access another fileserver > if the first fileserver becomes inaccessible for that > replicated data. > > + User-IDs and group-IDs are managed consistently across > all clients/servers. There is no dependence on local > /etc/passwd file. > > + Users can create their own group-ids and add members > to these groups. > > + If you have multiple database servers and one db server > fails the cell still functions and clients fallback to using > the remaining db servers automagically. > > + Authentication has from the start been done using Kerberos > which is much more secure than the NIS method used in NFS. > (OK, some implementations of NFS now have kerberos but > implementation is not consistent for all platforms). > > + Caching has always been used to provide good access to data > for second and subsequent access. > This also reduces network traffic. > > + Caching can be done in disk or RAM (for performance). > > + There is mutual authentication: not only do users have > to authenticate but servers do also. > > + In my experience, there have been fewer security problems > in AFS than NFS. > > + AFS has better "systems management" tools for administrators. > > + AFS administration can be done from any client machine. > > + AFS does not have the (IMHO ugly) client mount of server resource. > AFS filespace is consistent across all clients and has > "location independence": users do not need to know which server > to access to find a resource. Users just need the pathname. > "location mapping" is done at the server not the client. > (see also [3] "location independence") > > > I hope this helps. > -- > cheers > paul http://acm.org/~mpb > > References: > > [0] What is the Andrew Benchmark? > http://www.angelfire.com/hi/plutonic/afs-faq.html#sub3.18 > > [1] Graph of AFS versus NFS The Andrew Benchmark results > http://www.angelfire.com/hi/plutonic/images/andrew1.jpg > > [2] How does AFS compare with NFS? > http://www.angelfire.com/hi/plutonic/afs-faq.html#sub1.11 > > [3] AFS "location independence" > http://www.angelfire.com/hi/plutonic/afs-faq.html#sub1.05.b > > _______________________________________________ OpenAFS-info mailing list [EMAIL PROTECTED] https://lists.openafs.org/mailman/listinfo/openafs-info
