Use memory better

I have the feeling that we aren't using all the memory that we could be in our system (actually, I KNOW we aren't using all our memory), and would like to possibly speed up our ONLINE DS 7.2 system by maybe using memory more, if it might help. What stats should I be looking at? What should I consider tweaking? B. -- Please send administrative requests to admin@ASL.CA Brian P. Hampson ASL Analytical Service Laboratories Ltd System Administrator, Vancouver, BC (604)253-4188 ----------------- http://www.ASL.CA/ ---------------------------- I'm not speaking for the company <- They made me say that.

vmstat is the place to start. If you are not seing anything under the "pi" column, then you probably can increase memory usage. However, I sense that your main goal is to improve performance. Hate to say it, but before I decided that I needed to increase memory utilization, I'd check first to see if that is the bottleneck. Start out with onstat -p. If the read cache rate is much below 99%, then you might need to increase the buffer pool in the engine. If sar -u indicates that there is consistant %wio, then your IO complex is a bottleneck. You might be able to help by increasing the bufferpool and/or increasing read ahead. If iostat -x indicates a high %b or svc_t, then you might need to check on re-distribution of the disk layout. Also, it might be worth checking onstat -g iov. If the number of IO/sec is greater than 20, then you might need to add some more AIOVPs. Also, you want to see what looks like a descending pyramid across all of the aiovps. I'm a firm believer that you can't tune the database until you tune the system. Check to see where the bottlenecks are at the OS level, then check the engine. I'd recommend O'Reilly press for documentation on performance. Brian Hampson wrote: > I have the feeling that we aren't using all the memory that we could be in > our system (actually, I KNOW we aren't using all our memory), and would > like to possibly speed up our ONLINE DS 7.2 system by maybe using memory > more, if it might help. What stats should I be looking at? What should I > consider tweaking? > > B. > > -- > > Please send administrative requests to admin@ASL.CA > > Brian P. Hampson ASL Analytical Service Laboratories Ltd > System Administrator, Vancouver, BC (604)253-4188 > ----------------- http://www.ASL.CA/ ---------------------------- > > I'm not speaking for the company <- They made me say that.