Re: NUMAIOVPS setting

On Mon, 24 May 2004 10:47:48 -0400, Bent_Andy wrote: Here's the deal. The rule-of-thumb I gave is just that a rule for determining a starting point. Once you have a running system, run onstat -g iov, as Madison suggests. If there are a few aio VPs with io/wkup less than 1.0 then you are OK. If there are many such you can reduce them, but check across a peak load first. If there are none with io/wkup < 1.0 then you definitely need more AIO VPs. Art S. Kagel > HP-UX 11.11 - 7.31.fd5 - Baan IVc4 (OLTP) > > I have a question about numaiovps. Our current setting is 52 and we have 68 > chunks. Notes from a performance class say if onstat -g ioq shows maxlen > > 25 then time to add more aiovps. The system is not slow, I am only looking > to improve performance. > > Doing a search on cdi: > Art Kagel says "7.3x 1-1.5 per chunk plus a few extras." > > Madison Pruet: "Generally what I do is to check onstat -g iov. This > will display the io activity of each of the vps. What I look for is an > inverted pryamid on the aio VPs. The first should have a rather high io/s > field. At some point, this should approach zero. Once I have several aio > VPs that are below 1.0 io/sec, then I know that I've gone past the point > where adding aioVPs will do any good. You might want to examine onstat -g > iov to determine if you will gain any practical advantage by adding > additional aioVPs." > > Based on the output below, do I need to add more aio vps? > > onstat -g ioq> q name/id len maxlen totalops dskread dskwrite dskcopy > adt 0 0 0 0 0 0 0 msc 0 0 > 1 1387 0 0 0 aio 0 0 51 228 34 > 6 0 > > onstat -g iov > AIO I/O vps:> class/vp s io/s totalops dskread dskwrite dskcopy wakeups io/wup errors > msc 0 i 1.0 450204 0 0 0 450060 1.0 > 0 > aio 0 s 11.9 5621387 5565146 52144 0 5443752 1.0 > 0 > aio 1 i 11.0 5193030 5139920 52600 0 5034246 1.0 > 0 > aio 2 i 10.2 4812009 4755547 52519 0 4662685 1.0 > 0 > aio 3 i 9.4 4441062 4387927 52561 0 4305144 1.0 > 0 > aio 4 i 8.4 3960855 3908214 52144 0 3833875 1.0 > 0 > aio 5 s 6.8 3209144 3156686 52050 0 3092328 1.0 > 0 > aio 6 s 5.9 2770143 2717850 51842 0 2659455 1.0 > 0 > aio 7 s 5.3 2477346 2424829 52209 0 2375016 1.0 > 0 > aio 8 i 4.7 2216737 2165108 51409 0 2119768 1.0 > 0 > aio 9 s 4.2 1986931 1935263 51502 0 1896927 1.0 > 0 > aio 10 i 3.8 1788848 1737954 50739 0 1705304 1.0 > 0 > aio 11 i 3.4 1615150 1564533 50496 0 1537729 1.1 > 0 > aio 12 i 3.1 1465034 1414838 50089 0 1393282 1.1 > 0 > aio 13 i 2.8 1334102 1284303 49717 0 1266368 1.1 > 0 > ....... > aio 42 i 0.6 283402 238669 44730 0 202147 1.4 > 0 > aio 43 i 0.6 279139 234368 44765 0 194185 1.4 > 0 > aio 44 i 0.6 274000 229338 44660 0 186691 1.5 > 0 > aio 45 i 0.6 270863 226257 44604 0 179108 1.5 > 0 > aio 46 i 0.6 269319 224544 44774 0 172231 1.6 > 0 > aio 47 i 0.6 269227 224147 45079 0 165614 1.6 > 0 > aio 48 i 0.6 271074 225345 45728 0 158997 1.7 > 0 > aio 49 i 0.6 274434 228433 45996 0 152370 1.8 > 0 > aio 50 i 0.6 285348 238643 46699 0 145705 2.0 > 0 > aio 51 i 0.7 311878 264228 47649 0 138893 2.2 > 0 > > > Stats reset 130:46:18 ago. > > > > Thanks, > Andy Bent > > sending to informix-list

Art S. Kagel wrote: > Once you have a running system, run onstat -g > iov, as Madison suggests. If there are a few aio VPs with io/wkup less than > 1.0 then you are OK. If there are many such you can reduce them, but check > across a peak load first. If there are none with io/wkup < 1.0 then you > definitely need more AIO VPs. Correct me if I'm wrong: onstat -g iov has no column io/wkup in the output only io/wup which never falls below 1.0 here. Did you possibly thought of the column io/s? Reinhard