KAIO exceeds limit

Posted in 2006

Max Andersen — Wed, 25 Oct 2006 16:50:42 +0200 — source: Usenet: comp.databases.informix

Hi, I have 2 server setups, which slightly differ in specs. Both servers are IBM x336 with RAID 1 on 2 internal disks with RHEL4 installed(2.6.9-42.0.3.ELsmp). Both with IBM Informix Dynamic Server Version 10.00.UC5 1. One server is without hyperthreading and with a raw disk in LVM. 2. The second server is with hyperthreading and with a raw disk outside LVM. Just plain raw. But on the latter server(and only that one) we get this error when running a large job in informix: --- requested number of KAIO events (16384) exceeds limit (32) Please increase the value in /proc/sys/fs/aio-max-nr --- my sysctl -a | grep aio-max-nr, says (on both machines): fs.aio-max-nr = 65536 Is my selection of using LVM for raw disks, or the lack of KAIOOFF, etc. doing stuff differently? does using LVM provide these limitations? Or what should I boost the number up to? Sincerely Max Andersen