Long Checkpoints

Hi, i have a problem with long checkpoint runs on an informix 7.30 UC 10 running on linux. (Machine is a PIII 500 with 512 MB Memory). Sometimes checkpoints takes 15 to 25 seconds. During this times i have approximately 2000 to 2300 dirty LRU queues. an onstat -FR (with only 205 dirty, but Fg Writes and LRU Writes are also 0 with 2000 dirty). Fg Writes LRU Writes Chunk Writes 0 0 96227 address flusher state data 154f24c8 0 I 0 = 0X0 states: Exit Idle Chunk Lru 4 buffer LRU queue pairs priority levels # f/m pair total % of length LOW MED_LOW MED_HIGH HIGH 0 F 9984 99.5% 9935 0 9757 169 9 1 m 0.5% 49 0 49 0 0 2 f 9991 99.4% 9936 0 9758 171 7 3 m 0.6% 55 0 55 0 0 4 f 9993 99.5% 9944 0 9802 139 3 5 m 0.5% 49 0 49 0 0 6 f 9991 99.5% 9939 0 9753 180 6 7 m 0.5% 52 0 52 0 0 205 dirty, 39959 queued, 40000 total, 65536 hash buckets, 2048 buffer size start clean at 40% (of pair total) dirty, or 4000 buffs dirty, stop at 20% One thing wich i will try is to decrease the physical log and change the LRU max-min parameters to halve the size. But writing back 2000 queues makes approximately 4 MB of data. Could this really take 20 seconds to write back ? or can i tune some other parameters to get here a better performance ?. Thanks for help Uli -- Ulrich Eckhardt Tr@nscom http://people.frankfurt.netsurf.de/uli http://www.transcom.de Lagerstraße 11-15 A8 64807 Dieburg Germany