Hi John, On 22/07/10 19:56, JohnS wrote: > Try about 69Gbytes& What are you fiddling with? limits.conf? I think you read my mail too quickly and wrote a reply in similar speed. :) So did I read the original post too quickly and didn't realise he was complaining about the memory hole... You're right to say PAE goes to 64GB although in the past various distros had kernels compiled for different max addresses for various reasons. 4GB address space still applies to 32 bit apps. To use more than 4GB tricks as such (http://www.puschitz.com/TuningLinuxForOracle.shtml#ConfiguringVeryLargeMemory) need to be used. :) I haven't had to use these kinds of tricks for years since every machine I encounter has 64 bits and Oracle runs nicely on them perfectly happily. I miss reading through Puschitz's tips & tricks. Lately all Oracle versions run pretty much out of the box on CentOS/Upstream. No sense of satisfaction from seeing it running after battling with it for hours. :)