Specific to Linux, the NFS client uses standard filesystem caching which has a few pros and cons of it's own. Native GlusterFS uses up application space RAM and is a hard-set number that you must define. In our studio, our standard rollout is a 32GB RAM workstation, so native GlusterFS clients are told to use quite a bit of RAM for cache. When we connect up smaller VMs, often they have less RAM overall than we assign just for cache, and as such use NFS instead. -Dan ---------------- Dan Mons - R&D Sysadmin Cutting Edge http://cuttingedge.com.au On 29 April 2015 at 20:01, Kingsley <gluster@xxxxxxxxxxxxxxxxxxx> wrote: > On Tue, 2015-04-28 at 17:09 -0700, Dave Warren wrote: >> Bandwidth is also a consideration, the FUSE client will upload multiple >> copies based on the replica setting for the volume, so if the client is >> connected at 100Mb/s or over wifi, and the servers are cross-connected >> on a 10Gb/s backplane, having the client upload multiple copies vs >> having the NFS server handle the replicas may have an impact on very >> large files. >> >> Finally, NFS seems to have a lighter CPU footprint on the client, at the >> possible cost of higher server CPU load, although this is anecdotal >> (from my own experience), and probably a mixed bag. > > Oh I think I get it - the Gluster server daemons are also NFS server > daemons, so mounting via NFS you're still talking to a Gluster daemon on > the server ... and when writing to the server, the servers then handle > the replication themselves? > > I thought people were just putting the path to a brick in /etc/exports > and then just using nfsd that came with the OS, which I presume would > then break things. > > In that case, would this be a reasonable summary of mounting via NFS > instead of using the native fuse client? > > NFS pros: > * faster > * lighter weight on client resources (CPU, bandwidth) > * available to clients that have a standard NFS client but cannot > install gluster-fuse > > NFS cons: > * more load on servers > * writes complete on the client before the data is replicated > (which is faster, but less secure) > * if the server that the client happens to be connected to goes > down, the client loses access to the volume (whereas the fuse > client recovers and continues writing to the remaining notes) > > Does that seem about right? > > -- > Cheers, > Kingsley. > > _______________________________________________ > Gluster-users mailing list > Gluster-users@xxxxxxxxxxx > http://www.gluster.org/mailman/listinfo/gluster-users _______________________________________________ Gluster-users mailing list Gluster-users@xxxxxxxxxxx http://www.gluster.org/mailman/listinfo/gluster-users
