Jonathan B Bayer wrote: > Hello Discuss, > > I'd appreciate any comments on the following situation: > > A large, dual quad-core Intel 5500 CPU system > > Storage: 6 2 terabypte drives, in a RAID 1+0 setup. Raid controlled > by controller card. Total available storage is about 5.5 terabytes. > The drives are 7200 RPM > > OS drive: 2 160 gig drives in a RAID 1 setup, software controlled > > OS: CentOS 5.4 > > Virtualizatoni: KVM > > Virtual environments: Ubuntu 8.04 or 10.04 > > > Each virtual system will have a relatively small partition to boot > from. The data partition (/var) will be accessed via either NFS or > CIFS. The exported filesystems will be on the CentOS server, and > exported to each individual virtual system. Each virtual system will > access a different exported directory > > Each virtual system will be running PostGresql 8.2/8.3/8.4. In > addition to the database, they also store 50-100 k images > > So, here are my questions: > > 1. Which is better for performance, NFS or CIFS? >
Forget performance for a moment - how are you planning to use CIFS for /var? CIFS mounts are effectively user-level mounts, not system level. The permission mechanisms are completely different. You might get away with CIFS-mounting individual users' home directories, but not /var, the permission model is incompatible. I use CIFS exports to get more control and security at the user level (the server regulates the security, unlike NFS up to v3 where the client regulates the user-level security). I would only consider NFS (of the two) for /var. Since this is all on the same physical host, network speeds aren't a consideration, and you'll likely get full disk bandwidth using NFS, and it will be much easier to manage than CIFS (if you did manage to coerce the security). CIFS also tends to cause more overhead on Linux than NFS. However, since it *is* all one physical host, can't you just use the RAID filesystem directly? I haven't played with KVM yet, but this is certainly possible using VMware. - Richard _______________________________________________ Discuss mailing list Discuss@lopsa.org http://lopsa.org/cgi-bin/mailman/listinfo/discuss This list provided by the League of Professional System Administrators http://lopsa.org/
