Path: utzoo!utgpu!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!ames!ncar!tank!uxc!uxc.cso.uiuc.edu!uxg.cso.uiuc.edu!uxf.cso.uiuc.edu!jkj737 From: jkj737@uxf.cso.uiuc.edu Newsgroups: comp.sys.att Subject: Re: Making 3B2/310 faster Message-ID: <49800006@uxf.cso.uiuc.edu> Date: 19 Oct 88 23:43:00 GMT References: <260@beartrk.UUCP> Lines: 63 Nf-ID: #R:beartrk.UUCP:260:uxf.cso.uiuc.edu:49800006:000:2695 Nf-From: uxf.cso.uiuc.edu!jkj737 Oct 19 18:43:00 1988 /* Written 9:54 pm Oct 17, 1988 by clp@beartrk.UUCP in uxf.cso.uiuc.edu:comp.sys.att */ /* ---------- "Making 3B2/310 faster" ---------- */ I have a client who is using a 3B2/310 for a relatively small (<10000 records) database. There are some users who are complaining that the machine is too slow and would like to enhance the performance. But they would like to do it inexpensively if possible. The current configuration is: 3B2/310, 2 Meg Memory, 72 MB disk, 2 Ports cards, XM box with 23 MB tape drive. Software is Sys V, rel 2.1. I've talked with some other users who suggested that A) more memory might help, B) a second disk might help, C) changing to Sys V, rel 3 might help. I'm open to any suggestions, but in particular I'm curious about the following: /* End of text from uxf.cso.uiuc.edu:comp.sys.att */ The first thing I would do is set up the performance utilities that come with Unix (sar(1m) and the like) and take a weeks worth of data under normal load. Take a look at disk activity, and memory swapping stats to see where the bottleneck is. If you have a LOT of disk activity and very little memory swapping, you probably need a second disk to offload some of the work. Unix works best with swap and / on one disk /usr on second. This minimizes head movement and reduces the amount of time waiting for i/o (wio). It balances the disk use more evenly between both drives. If you have a LOT of memory swapping, you don't have enough memory so Unix is constantly swapping memory out to disk which will hurt if you also are doing a lot of disk activity as well. You probably should look at getting more memory. You should also look at performance verses number of users. The 310's ports cards are dumb (almost) and cause more overhead than the new eports we use on the 600. You could have too many users for a 310. Release 3.1 does have nice features like demand paging and shared libraries, but these come at a price. The overhead is slightly higher, so depending of machine use it may or may not help. I have found that our 300 running 3.1 is a total dog. A 310 should fair a little better. As my computer architecture professor said, "The only way to may a good decision is to not make a stupid one." (ie. don't change ANYTHING until you look are the system activity reports for the normal system load and verify the bottlenecks.) Be sure to use all the options of SAR(1M) available. #include Jeff Johnson Global Information Systems Technology, Inc. 1800 Woodfield Drive Savoy, IL 61874 UUCP: ...!uiucuxc!gistqa!jjohnson ARPANET: jjohnson%gistqa@uxc.cso.uiuc.edu -or- jkj737%uxf@uxc.cso.uiuc.edu