Re: checkpoint interval

In article <6i77dj$11l$1@news.xmission.com>, Steve Romankiw <sromankiw@execrisk.com> writes > >David: > >You mentioned setting "log buffer to 2". Is that platform specific? I thought >the >minimum was 16? > According to the online Admin Guide Version 7.1 Page 38-28. It is expressed in K and the minimum is 2* the page size. Hence a) run onstat -b and look at the last line for buffer size, this is the page size in bytes. b) Divide by 1024 and multiply by 2. Use this value... PHYSBUFF should also be looked at. The minimum value for this is the page size in k. This CAN be set to 2 assuming a 2K page size. >SteveR > >David Williams wrote: > >> In article <6hqfj6$jk9$1@news.xmission.com>, Harold Luse >> <hluse@vth.colostate.edu> writes >> > >> >Sahrul, >> > >> >We have been having similar problems with 7.23 UC6 on AIX 4.2.1. >> > >> >Our routine checkpoint intervals are no more than 2 seconds. However, >> >approxiamtely two to three times each day, we get excessive checkpoint >> >intervals of anywhere from 80 to 250 seconds. >> > >> >Through the use of a shell script and some onstat commands we have >> >tracked the problem down to the logical buffer not being able to flush to >> >the logical logs on disk (we use unbuffered transaction logging). >> > >> Check the size of the logical log buffer in your $ONCONFIG file. >> >> Run onstat -l and check pages/io. I would imagine it is between >> one and two. Reduce the logical log buffer size to 2. >> >> >Are you noticing the same thing? >> > >> >Anyone else who cares to comment please jump in. >> > >> >==================================================================== >> >Harold Luse Phone: (970) 491-4120 >> >Veterinary Teaching Hospital Fax: (970) 491-1275 >> >Colorado State University Pager: (970) 229-8173 >> >Fort Collins, Colorado USA E-mail: hluse@vth.colostate.edu >> >==================================================================== >> > >> >> -- >> David Williams >> >> Maintainer of the Informix FAQ >> Primary site (Beta Version) http://www.smooth1.demon.co.uk >> Official site http://www.iiug.org/techinfo/faq/faq_top.html >> >> I see you standin', Standin' on your own, It's such a lonely place for you, >For >> you to be If you need a shoulder, Or if you need a friend, I'll be here >> standing, Until the bitter end... >> So don't chastise me Or think I, I mean you harm... >> All I ever wanted Was for you To know that I care > > > >-- >----------------------------------------------------------------- >Steve Romankiw + >Executive Risk Inc. + >DBA + email: sromankiw@execrisk.com >82 Hopmeadow Street + work: (860) 408-2474 >Simsbury,CT 06070 + fax: (860) 408-2139 >----------------------------------------------------------------- > > -- David Williams Maintainer of the Informix FAQ Primary site (Beta Version) http://www.smooth1.demon.co.uk Official site http://www.iiug.org/techinfo/faq/faq_top.html I see you standin', Standin' on your own, It's such a lonely place for you, For you to be If you need a shoulder, Or if you need a friend, I'll be here standing, Until the bitter end... So don't chastise me Or think I, I mean you harm... All I ever wanted Was for you To know that I care