Hi out there, I've some little questions, perhaps you can help me... At the moment, we're planning our new clustered ERP system which consists of a java application server and a postgresql database. The hardware, which is actually used for that system isn't able to handle the workload (2 Processors, load of 6-8 + 12GB Ram), so it is very, very slow - and that although we already deactived a lot of stuff we normally want to do, like a logging and something like that... We've already choosen some hardware for the new cluster (2x quadcore Xeon + 64GB Ram should handle that - also in case of failover when one server has to handle both, applicaton and database! The actual system can't do that anymore...) but I also have to choose the filesystem hardware. And that is a problem - we know, that the servers will be fast enough, but we don't know, how many I/O performance is needed. At the moment, we're using a scsi based shared storage (HP MSA500G2 - which contains 10 disks for the database - 8xdata(raid 1+0)+2x logs(raid1) ) and we often have a lot wait I/O when 200 concurrent users are working... (when all features we need are activated, that wait I/O will heavy increase, we think...) So in order to get rid of wait I/O (as far as possible), we have to increase the I/O performance. Because of there are a lot storage systems out there, we need to know how many I/O's per second we actually need. (To decide, whether a storage systems can handle our load or a bigger system is required. ) Do you have some suggestions, how to measure that? Do you have experience with postgres on something like HP MSA2000(10-20 disks) or RamSan systems? Best regards, Andre
