Re: Informix Tuning Problem

Andy Leung wrote: > My server run very slow for this few weeks.. I've checked the %cache go 99%.. > > Hardware : > IBM - H80 , 4 CPU , 2G Ram , HD x 2 > > dskreads pagreads bufreads %cached dskwrits pagwrits bufwrits %cached > 25899 119543 30538756 99.92 97670 146260 2077545 95.30 > > ONCONFIG : - > > MULTIPROCESSOR 1 # 0 for single-processor, 1 for multi-processor > NUMCPUVPS 4 # Number of user (cpu) vps > SINGLE_CPU_VP 0 # If non-zero, limit number of cpu vps to one > LOCKS 150000 # Maximum number of locks > BUFFERS 80000 # Maximum number of shared buffers > NUMAIOVPS 2 # Number of IO vps > PHYSBUFF 1024 # Physical log buffer size (Kbytes) > LOGBUFF 500 # Logical log buffer size (Kbytes)> LOGSMAX 25000 # Maximum number of logical log files > CLEANERS 8 # Number of buffer cleaner processes > SHMBASE 0x30000000 # Shared memory base address > SHMVIRTSIZE 98304 # initial virtual shared memory segment size > SHMADD 32768 # Size of new shared memory segments (Kbytes) > SHMTOTAL 524288 # Total shared memory (Kbytes). 0=>unlimited > CKPTINTVL 120 # Check point interval (in sec) > LRUS 8 # Number of LRU queues > LRU_MAX_DIRTY 60 # LRU percent dirty begin cleaning limit > LRU_MIN_DIRTY 50 # LRU percent dirty end cleaning limit > LTXHWM 50 # Long transaction high water mark percentage > LTXEHWM 60 # Long transaction high water mark (exclusive) > TXTIMEOUT 0x12c # Transaction timeout (in sec) > STACKSIZE 32 # Stack size (Kbytes)> > Any idea ? There isn't much to go on here - you will need to post more information. This list I pinched from a post from Art S. Kagel: System description: # CPUs, disk farm (RAID levels, # spindles, local or SAN, etc.), contents of you ONCONFIG file, elapsed time since onstat -z was last run (or since startup if never since) output from: onstat -p onstat -P onstat -d onstat -D onstat -g glo onstat -g iov onstat -g iof onstat -F onstat -R onstat -l onstat -T onstat -g dsc onstat -g dic onstat -g prc onstat -g env onstat -g seg Based on what you have put above, I would say NUMAIOVPS is very low indeed (suggest 20-30) and that with 2Gb RAM you could have more BUFFERS. I don't even know what version of IDS you are running. Or the answer could be UPDATE STATISTICS. The best thing is to read the Performance Guide for your version of Informix. A quick search on google would find this. Ben.

"Ben Thompson" <ben@nomonitorsoftspam.com> wrote in message news:10hn3hctpj28u45@corp.supernews.com... > Andy Leung wrote: > > Based on what you have put above, I would say NUMAIOVPS is very low > indeed (suggest 20-30) .... How can you say that without knowing if he is using kaio, or how many chunks he has?

Neil Truby wrote: > "Ben Thompson" <ben@nomonitorsoftspam.com> wrote in message > news:10hn3hctpj28u45@corp.supernews.com... > >>Based on what you have put above, I would say NUMAIOVPS is very low >>indeed (suggest 20-30) .... > > How can you say that without knowing if he is using kaio, or how many chunks > he has? I probably can't fully justify that statement as you point out. Personally I never use KAIO as I don't administer any systems that support it. For KAIO it's 1 plus 2 for every buffered chunk. I suppose my get-out clause was "read the performance guide" which contains full details of how to tune this value. Ben.