Re: Buffer writes

Robert Moayedzadeh wrote: > > I just had a question pertaining to buffer writes my system is currently > maintaing 70-75% on the buffer writes. I was told that it should be closer > to 95%... Any thoughts. Actually 95% is good for READ cache and 85% is good for WRITE cache. Write caching is to do with how many times the same page is written back to disk. If the page can hang around for longer and wait for all changes, then IO can be reduced, giving a higher cache figure. So generally you would look to increase LRU_MAX_DIRTY & LRU_MIN_DIRTY and or decrease the frequency of checkpoints. In general though, tuning of checkpoint duration tends to take precedence over tuning WRITE cache. Cheers, -- Mark. +----------------------------------------------------------+-----------+ |Mark D. Stock - Informix SA http://www.informix.com |//////// /| |mailto:mdstock@informix.com http://www.informix.com/idn |///// / //| |http://www.iiug.org +-----------------------------------+//// / ///| | Tel: +27 11 807 0313 |If it's slow, the users complain. |/// / ////| | Fax: +27 838250 2325 |If it's fast, the users keep quiet.|// / /////| |Cell: +27 83 250 2325 |Therefore, "No news: travels fast"!|/ ////////| +----------------------+-----------------------------------+-----------+