On Mon, Apr 18, 2022 at 09:43:38PM +0000, Eric Robinson wrote: > New kernel versions are released fairly often. What are the rules > about upgrading DRBD when that happens? Is it always necessary, or are > there certain thresholds within which it is okay to upgrade the kernel > without rebuilding DRBD? Rebuilding DRBD every time is pretty > disruptive.
"depends", but in general that is how things work, there are no stable kABI guarantees from the Linux kernel itself. So you have to rebuild external modules. This is for example why dkms exists. In more detail it depends on the distribution. RHEL guarantees a stable kABI for certain symbols. Unfortunately sometimes even they make mistakes and break it, but one usually gets away with relatively few builds. Debian tries to keep a stable kABI, Ubuntu does not seem to do so. Needless to say that we for example test for new RHEL kernels and compat and provide new binary modules for our customers. They just upgrade and don't have to worry. Same for Debian - we build when we need to - we build every Ubuntu kernel release. For the other distros it depends on their model (which roughly depends on how "good" their RHEL clone actually is). Even with rotating out old kernels rather quickly, we get 3 figure kernel numbers we build for easily. Regards, rck _______________________________________________ Star us on GITHUB: https://github.com/LINBIT drbd-user mailing list drbd-user@lists.linbit.com https://lists.linbit.com/mailman/listinfo/drbd-user
