maxlen in onstat -g ioq

Again a performance issue. When I run onstat -g ioq, I find several AIO I/O queues that have high maxlen numbers, even when there haven't been too much activities. Aren't these numbers too big? [How] Can I change that? (Informix 9.30.UC2 on Linux SLES7) Many regards, R'diger ----- AIO I/O queues: q name/id len maxlen totalops dskread dskwrite dskcopy adt 0 0 0 0 0 0 0 msc 0 0 1 31027 0 0 0 aio 0 0 47 110 9 2 0 pio 0 0 1 183842 0 183842 0 lio 0 0 1 516069 0 516069 0 gfd 3 0 4 49580 45308 4272 0 gfd 4 0 151 3276699 3219689 57010 0 gfd 5 0 1 1988702 1988702 0 0 gfd 6 0 8 1996296 1996281 15 0 gfd 7 0 1 2272998 2272998 0 0 gfd 8 0 30 2850624 2847856 2768 0 gfd 9 0 150 3078305 3059903 18402 0 gfd 10 0 150 4642468 4614810 27658 0 ... gfd 18 0 150 486277 245885 240392 0 ...

Rüdiger, This is normal. At checkpoint time online writes out the dirty buffers in batches of 150 each for every chunk (300 if the chunk is mirrored). If you have chunks with many dirty pages maxlen will reach 150. Don't ask me why it's 151 in one case. I don't know. Michael Rüdiger Mähl wrote: > Again a performance issue. > > When I run onstat -g ioq, I find several AIO I/O > queues that have high maxlen numbers, even when > there haven't been too much activities. > Aren't these numbers too big? > [How] Can I change that? > > (Informix 9.30.UC2 on Linux SLES7) > > Many regards, > > Rüdiger > > ----- > AIO I/O queues: > q name/id len maxlen totalops dskread dskwrite dskcopy > adt 0 0 0 0 0 0 0 > msc 0 0 1 31027 0 0 0 > aio 0 0 47 110 9 2 0 > pio 0 0 1 183842 0 183842 0 > lio 0 0 1 516069 0 516069 0 > gfd 3 0 4 49580 45308 4272 0 > gfd 4 0 151 3276699 3219689 57010 0 > gfd 5 0 1 1988702 1988702 0 0 > gfd 6 0 8 1996296 1996281 15 0 > gfd 7 0 1 2272998 2272998 0 0 > gfd 8 0 30 2850624 2847856 2768 0 > gfd 9 0 150 3078305 3059903 18402 0 > gfd 10 0 150 4642468 4614810 27658 0 > ... > gfd 18 0 150 486277 245885 240392 0 > ... -- === Michael Mueller ================== Tel. + 49 8171 63600 Fax. + 49 8171 63615 Web: http://www.mm.kay-mueller.de http://www.planets.kay-mueller.de ======================================