tbstat -p - bufreads -ve value and %cached is zero

Hi netters, I'm currently facing a strange happening..... Just recently, I've found out that the statistics shown with tbstat -p is as below : dskreads pagreads bufreads %cached dskwrits pagwrits bufwrits %cached 2532970 7981185 -1276277831 0.00 539360 950409 5672084 90.49 isamtot open start read write rewrite delete commit rollbk -886595861 24220961 38590224 1671926502 717775 1922977 483209 32010383 7057 ovtbls ovlock ovuser ovbuff usercpu syscpu numckpts flushes 0 0 0 0 305128.27 16726.45 3500 8086 bufwaits lokwaits lockreqs deadlks dltouts lchwaits ckpwaits compress 236446 7292 538614142 1 0 1986431 4873 46069 The Informix engine 5.0 is still running fine but reading performance is definitely slow. In total I have 53 users and when I do a tbstat -u : user locks disk reads diskwrits ctl 1 71125 24 The disk reads numbers are much larger than the diskwrits. Then doing a tbstat -l : Physical log : Buffer Bufsize Bufused Numpages Numwrites pages /IO P-1 16 7 198781 14667 13.55 Physize Phypos Phyused % Used 4437 4367 55 1.24 logical log: Buffer Bufsize Bufused Numrecs Numpages Numwrites Recs/Page Pages/IO L-1 16 0 11230766 548083 390429 20.49 1.40 My shared memory size is 7312 Kbytes Any suggestion what is happening to my cache value? Thanks in advance. regards, cynthia leong Hewlett-Packard, Singapore cynthia@hpsgcip1.sgp.hp.com