Re: read and write cache percentages

Art S. Kagel wrote: > > Everything looks fine except you definitely need many more buffers. > I'd start with 100,000 and work from there. Also with 240 users you > can need more than 16 LRUS which is verified by your enormous bufwaits > ratio of 25%, it should be below 7%. Go for broke and configure 127 > LRUs (128 triggers a harmless but annoying error message at startup). Vic, I think you will need to increase CLEANERS as well. Besides read and write cache percentage you should pay attention also to other parameters, e.g. ROOTPATH - without link you can have problems in the future DBSPACETEMP - one dbspace definitely is not enough PHYSDBS - in rootdbs ? Not good Where are your logfiles? They should be in different dbspace. LTAPEDEV /dev/null 240 users and you're not saving transaction information? Is it OK? HTH Vardan -- vaar@geocities.com > Also I see you are runing on HP. HPUX is aggressive about aging long > running processes. You should have NOAGE set it your 7.22 supports it, > check the release notes for support and possible patches. Also I > notice very long checkpoints which will only get worse with more > buffers. Reset LRU_MAX_DIRTY to a value between 2 and 10 and > LRU_MIN_DIRTY to a value between 0 and 5 and adjust to reduce > checkpoint duration to an acceptable level. > > Just NOAGE and increasing LRUs and buffers and you will see a > significant improvement and reduced system impact from the bufwait > spins. > > Art S. Kagel > > Vic Newman wrote: > > > > In article <379345E3.E314EBB4@bloomberg.net>, > > kagel@bloomberg.net wrote: > > > Post your ONCONFIG file, onstat -R, onstat -p, onstat -F, onstat -m, > > > onstat -l outputs and we'll look it over.> > > > > > Art S. Kagel > > > > > > Vic Newman wrote: > > > > > > > > In article <7muke7$lt8$1@nnrp1.deja.com>, > > > > Yuri Dovgart <y_dovgart@tci.ukrtel.net> wrote: > > > > > In article <7mrhba$pd7$1@nnrp1.deja.com>, > > > > > Vic Newman <klball@my-deja.com> wrote: > > > > > > We are running 7.2 on hp 9000 with approx 240 users. I > > noticed > > > > the > > > > > > write cache percentage was 67%, the read cache percentage was > > 97%. > > > > Is > > > > > > the 67% ok. Are there any paramenters we should be looking at > > to > > > > > > increase this write cache percentage or is 67% an acceptable > > level? > > > > > > > > > > Generally speaking 67% is too low. But this number depends on the > > type > > > > > of activities, performed in your system. For example, if you have > > 100 > > > > K > > > > > reads with cache ratio 98% and 1 K writes with cache ratio 70 % - > > I > > > > > think it's OK. But if balance between reads and writes is about > > 50/50 > > > > - > > > > > you need tuning. So, it's your choice is it OK, or not. > > > > > > > > > > First step to increase cache ratio is to add more BUFFERS. Check > > > > column > > > > > ovbuff in "onstat -p" output - if there is some number there, you > > > > > certainly need to add some buffers. Other steps, such as tuning > > LRU > > > > > queues and flushing params are dependent on the system profile. To > > > > help > > > > > you in this tuning, we need your "onstat -a" and ONCONFIG file. > > > > > > > > > > -- > > > > > With best regards, Yuri Dovgart, > > > > > SAP R/3, Informix consultant, > > > > > "Telecominvest" company. > > > > > E-mail y_dovgart@tci.ukrtel.net > > > > > > > > > > Sent via Deja.com http://www.deja.com/ > > > > > Share what you know. Learn what you don't. > > > > > > > > > > > > > The ovbuff in onstat -p is 0. The output from ostat -a is quite > > lengthy > > > > and I did not want to post the entire output because of that. Is > > there > > > > a specific part of in that is helpful? > > > > > > > > Sent via Deja.com http://www.deja.com/ > > > > Share what you know. Learn what you don't. > > > > > > > Listed below are the onconfig and onstat R, p, f, m and l. > > Thanks for your input. > > > > Vic > > > > #*********************************************************************** > > *** > > # > > # INFORMIX SOFTWARE, INC. > > # > > # Title: onconfig.sales_prod > > # Description: INFORMIX-OnLine Configuration Parameters > > # > > #*********************************************************************** > > *** > > > > # Root Dbspace Configuration > > > > ROOTNAME rootdbs # Root dbspace name> > ROOTPATH /dev/AR1LUN4/rlv0 # Path for device containing root > > dbspace > > ROOTOFFSET 0 # Offset of root dbspace into device > > (Kbytes) > > ROOTSIZE 100000 # Size of root dbspace (Kbytes)> > > > # Disk Mirroring Configuration Parameters > > > > MIRROR 1 # Mirroring flag (Yes = 1, No = 0) > > MIRRORPATH # Path for device containing mirrored> > root > > MIRROROFFSET 0 # Offset into mirrored device (Kbytes)> > > > # Physical Log Configuration > > > > PHYSDBS rootdbs # Location (dbspace) of physical log > > PHYSFILE 40000 # Physical log file size (Kbytes)> > > > # Logical Log Configuration > > > > LOGFILES 40 # Number of logical log files > > LOGSIZE 1000 # Logical log size (Kbytes)> > > > # Diagnostics > > > > MSGPATH /var/informix/sales_prod.log # System message log file > > path > > CONSOLE /var/informix/sales_prod.con # System console message > > path > > ALARMPROGRAM /usr/informix/etc/autolog.sales # Alarm program path > > > > # System Archive Tape Device > > > > #TAPEDEV /dev/null # Tape device path > > TAPEDEV /dev/rmt/0m # Tape device path > > TAPEBLK 64 # Tape block size (Kbytes) > > TAPESIZE 2000000 # Maximum amount of data to put on tape > > (Kbytes)> > > > # Log Archive Tape Device > > > > LTAPEDEV /dev/null # Log tape device path > > #LTAPEDEV /dev/rmt/0m # Log tape device path > > LTAPEBLK 64 # Log tape block size (Kbytes) > > LTAPESIZE 2000000 # Max amount of data to put on log tape > > (Kbytes)> > > > # Optical > > > > STAGEBLOB # INFORMIX-OnLine/Optical staging area > > > > # System Configuration > > > > SERVERNUM 4 # Unique id corresponding to a OnLine> > instance > > DBSERVERNAME sales_prod # Name of default database server> > DBSERVERALIASES salse_net_prod # List of alternate dbservernames > > NETTYPE ipcshm,3,400,CPU # Configure poll thread(s) for nettype > > NETTYPE soctcp,1,200,NET # Configure poll thread(s) for nettype > > DEADLOCK_TIMEOUT 60 # Max time to wait of lock in> > distributed env. > > RESIDENT 0 # Forced residency flag (Yes = 1, No = > > 0) > > > > MULTIPROCESSOR 1