On Jan 27, 2008 8:28 PM, Rainer Duffner <rainer@xxxxxxxxxxxxxxx> wrote: > > Am 28.01.2008 um 02:36 schrieb Terry: > > > > > > > Good questions: > > 1) Do you have concurrent writes to the same file from different > > nodes? > > 1a) No > > > Well, that's one of the things GFS is good at ;-) > > > > 2) How many nodes do you have? > > 2a) 3 to start, probably won't go beyond 12 > > > > > OK, that's still in the range GFS can handle (AFAIK). > > > > I appreciate alternative ideas to NFS. NFS could possibly introduce > > performance issues (comments here appreciated). > > > One problem might be that NFS was never supposed to run on GBit- > networks. > Thus there is overhead. > But, OTOH, the vendors I mentioned have managed to squeeze a lot of > performance out of NFS. > It's also a question of optimizing/matching NFS clients and servers. > > > > The majority of the > > system is write. I would say 80%. > > > > Do you have a lot of small files? > Small files are usually what degrades GFS-performance. > > As I mentioned, if your requirements are tending to be more grid- > computing related, best ask somebody with a grid-computing background. > Though, they may think in dimensions where 12 nodes is what they have > at home in a VMware-team. > ;-) > > Personally, I would be very careful to consider GFS for a system with > a lot of writes (concurrent to a file or not). > The reason is that it is most times impossible to predict the > behavior of GFS with a certain application-load-pattern at a given > cluster-size - there are just too many variables. > This is, of course, also true for NFS - but there's simply much more > NFS out there "in the field" and you can *always* find someone who > does nearly (or exactly) the same thing as you want to do and then > make better educated guesses about how the system will perform. > > So, if you want to go with GFS: build your cluster, see if it > performs, if it doesn't perform: work with your integrator and RedHat > and see what they can do. > If that doesn't help: scrap it and install an NFS server on some box > (use Solaris+ZFS - though there are other issues with that, too, of > course). > > > > cheers, > Rainer > -- > Rainer Duffner > CISSP, LPI, MCSE > rainer@xxxxxxxxxxxxxxx Good tips. Yes, a ton of small files and many directories. 56,000,000 files roughly today. I wonder how an active-active NFS would fare in this type of environment. -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
