Leonardo Vilela Pinheiro wrote: > As an Enterprise operating system, CentOS provides software seamless > compatibility (if this can be called compatibility) inside the same > release (as Centos-4, or Centos-3, or Centos-2). Correct me if I´m wrong. yes, this is correct. However, you might be more in 'sync' with reality by looking at this issue from a slightly different angle... the aim is that as packages move Release's through the lifecycle of a distro release ( eg. CentOS - 4 ) , the aim is not break either the ABI ( so your own apps function right ), the config file formats and expected behavior ( so your dont break config's ), and the filesystem layout ( so things continue to stay where they started off with ). And this is maintained even when Packages move through their own release cycle ( eg. in C-4.4 mozilla has been replaced with the Seamonkey suite, but whatever you may have built against mozilla-nss and nspr will continue to work fine, with no need for a rebuild ). > I know that if Intel (or whatever) releases a driver for CentOS 4.1, one > may think that it must be a new driver, possibly unstable. But let´s it will be unstable, but thats not the only thing, I would trust the distro vendor to have done a lot more stability testing with various install options and environments than Intel ( or any hardware vendor ) would have. In most cases the hardware vendor is only testing on 1 architecture, and never on a continuous basis ( when was the last time intel had a driver for each kernel release from upstream ? ). However, its a mixed bag, both these people - h/w vendor and distro vendor - need to work together in the Linux scape, to make sure the user gets the best possible experience, support and functionality.( drifting OT ? ) > suppose a vendor gives me a driver which is new but completely stable > (just suppose, because this is just a conceptual question). Will this > driver be compatible with every (forward and/or backward) "sub-versions" > of CentOS 4 ? CentOS-4 is the distro, I would presume that the driver is kernel defendant mostly. Kernel updates, while they do happen at release cycle update, also take place between these release cycles. And to answer your question, yes - the Kernel's abi does not change. If it broke, report it as a bug. If the driver has userland dep's - its upto the hardware vendor to ensure that the driver works for all release cycle's. There is absolutely nothing that the distro vendor can do in such cases. Having said that, I've not yet seen anything break in this manner. What you also might want to keep in mind is that drivers within the distro kernel are updated and new drivers added in. So its possible, what while you needed an external Vendor driver to make some h/w function properly with 2.6.9-5.EL kernel, the driver was then included in the distro supplied, 2.6.9-11.EL. Once you look at things from a slightly larger perspective, the kernel/driver issue falls into place. HTH -- Karanbir Singh : http://www.karan.org/ : 2522219 at icq