I have a machine which started life on Linux 2.4.x, then was updated to Linux 2.6.x. Now it's been updated to Linux 2.6.18. Each time, only kernel has been updated. The same original set of tools (binutils, glibc...) remain (obviously this is not ideal).

My question is, should I expect the machine to function fine, given the kernel updates and older tools? Or, are there scenarios where kernel version x.y.z breaks compatibility, and you need a new set of tools?

If it matters, the most exotic things the machine does are software RAID (but this can go away), and NFS.