Re: Online 7.10 performance on Stratus and others

In article <3qiuao$1apm@firehose.mindspring.com>, ekelley@mindspring.com (Ed Kelley) wrote: > >Some additional things you might look at: > >Does your version of UNIX support kernel asynchronous IO? If so, then >informix allocates one virtual processor per CPU to handle IO. Here >again, the more cpus you have the better your performance will be. yes, we already looked into this. >Also, are you using any kind of RAID setup for your rawdisk? This can >have a tremenedous negative impact on throughput, especially for >writes. We use a RAID 5 setup. Writes are relatively slow but our >reads (98% of what we do, scream). Monitor your SAR output during your >testing and examine you onstat -p output to try and identify your >bottle necks. Use onstat -D to monitor actual chunk IO. Are you using >data partitioning? If you are not using a RAID configuration, then you >might want to consider it. If you are using RAID, then avoid >partitioning. > No, we do not use RAID-5 but we do use the Stratus hardware disk mirroring facilities. During Informix database administration courses Informix already advises to be careful when mixing Online facilities with hardware/operating system facilities because they can be contra-productive. --------------------------------------- Met vriendelijke groet (dutch for: with kind regards) Jan-Evert Zondag email: zondag@xs4all.nl