Re: LRU Parameters

In article <01bd6c5b$658ff980$8da4d2cc@scott>, Scott Kolaya <skolaya1@nycap.rr.com> writes >Values of: > >LRU_MAX_DIRTY 3 >LRU_MIN_DIRTY 2> >are commonly used for OLTP processing to decrease the length of a >checkpoint. How long are your checkpoints taking? They should be very >short with those values, but your write cache will suffer. > Agreed, some people even go as low as 1 and 2. Remember this is a %age of BUFFERS. Multiply BUFFERS*(buffer size from onstat -b in K) * LRU_MAX_DIRTY this gives the amount of data which could be waiting to be written to disk during a checkpoint. Obviously you do not want this to get too high. >Scott Kolaya > > >Jo'o Carvalho <joao.s.carvalho@mail.telepac.pt> wrote in article ><6hfc5q$pvs$1@duke.telepac.pt>... >> Hi all ! >> >> I've got a doubt and I would like to know if someone can answer it: >> >> In a dual processor IBM 6000 with AIX 4.2.1, 250Mb RAM and >> running Informix 7.24 UC1, I found those values in ONCONFIG: >> >> MULTIPROCESSOR 1 >> NUMCPUVPS 1 >> SINGLE_CPU_VP 1 >> LOCKS 25000 >> BUFFERS 20000 >> CLEANERS 4 >> LRUS 32 >> LRU_MAX_DIRTY 3 >> LRU_MIN_DIRTY 2>> >> If I'm not mistaken the last two values are in percentage and >> if so, aren't they rather odd?. >> These values make sense to anyone? >> >> Any help apreciated in advance! >> >> Jo'o Carvalho >> joao.s.carvalho@mail.telepac.pt >> >> >> >> >> >> -- 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