We are planning to expand our lustre setup. Do anyone have any advice on what will be the most efficient solution for OSS server hardware? Should we buy few fat nodes, for ex. with two quad core cpus with lots of memory? Or rather many simple boxes with less cpus, one single core or dual core cpu and little memory (1 GB per node). As it looks now we can either buy two fat OSSs with two dual FC controllers each to the raids. Or, four simple pizza boxes with one dual FC controller each to the raids. Using 1.5TB per OST we get a total of 8 OSTs in this system, so will fewer OSTs per OSS be beneficiary? Four simple boxes seems to be cheaper than two fat nodes. Bugzilla entry 2573 indicates that large memory pools are of little benefit on the OSS side. Do anyone have a rule of thumb for the recommended memory size per OST on an OSS? We use infiniband between the clients and the OSS/MDS. Any insight is greatly appreciated. We do this extension primarily to resolve an issue with our current lustre setup where we run two file systems, home and scratch, on a shared dual server setup where the MDS and OSS are on the same physical hardware. When we have high io on scratch the home file system becomes very inresponsive for interactive use, ls on a catalog with 200 files takes 60 seconds and so on. We hope to solve this by moving the scratch OSSs out of this hardware and only keep the scratch MDS on the old system. Regards, r. -- The Computer Center, University of Troms?, N-9037 TROMS? Norway. phone:+47 77 64 41 07, fax:+47 77 64 41 00 Roy Dragseth, High Performance Computing System Administrator Direct call: +47 77 64 62 56. email: royd@cc.uit.no