Increasing vCPU's on Oracle DB server

[NCLSInfoTech]

My company has an application that currently runs on a physical Solaris 10/SPARC server with ISAM databases.   We want to move to a RHEL 5/Oracle VM.   The application vendor says that the virtual machine requires the same amount of RAM and same number of CPU's (4) as a physical server, which seems like overkill.

My first question is can the number of vCPU's be increased on the VM after installation if I find I need more CPU resources without having any ill effects on the VM and Oracle in particular ( I was thinking of starting with 2 vCPU's and working up if needed)?

Second question - the # cores/socket setting - for 2 vCPU's is there any benefit in setting 2 cores/socket rather than 1 (host has 2 quad-core CPU).   If I understand what I've read correctly, that really only helps when the # of available cores exceeds the hard limit of CPU's in an OS.

Thank you for your help.

[sflanders]

Assuming you are using a newer RHEL version with VMware Tools installed you can hot add CPU and memory to the VM with no ill effect and without downtime. Otherwise, you can add additional resource with the VM powered off as well. In most circumstances physical to virtual resources are not one-to-one and unlike physical servers throwing hardware at the system does not necessary result in better performance in the virtual world. Basically, you are correct in your assumptions!

Hope this helps!

[NCLSInfoTech]

Yes it does - thank you!