OpenVZ Forum: Support » Multiple kernel versions

Home » General » Support » Multiple kernel versions

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: Multiple kernel versions [message #29897 is a reply to message #29894]

Tue, 29 April 2008 06:07

khorenko
Messages: 533
Registered: January 2006
Location: Moscow, Russia

Senior Member

Hi.

Yes, in general you are right - all the Containers on a Node use the same kernel and you cannot run different kernels in different Containers using OpenVZ technology, but!...

Kernel API is really very stable and kernel provides a good backward compatibility and thus for most userspace apps is does not matter what kernel do they use. (Ok, this is true in only one direction - surely newer kernel might provide some new syscalls and if an app uses it, it will fail if one tries to run the app under an older kernel where this syscall was not implemented.)
In particular i highly believe that a Container with CentOS 3 will work fine on a Node with 2.6.18-x ovz kernel.

Moreover, OpenVZ has a possibility to change the kernel name reported inside a Container by 'uname' - might be helpful if some app uses this.

The other problem you'll face trying to create a Container with CentOS 3 - absence of a precreated CentOS 3 template. OpenVZ project started when CentOS 4 has been already widely used (and thus kernel 2.6.9) so up to now seems that nobody created/shared a template for CentOS 3. But you can create a template yourself and may be even share it. Smile