Kmorph is a new open-source project for rebootless kernel crash recovery, Phoronix reports. It claims as little as about two seconds of downtime to bring services like Nginx back after a kernel crash.
How it works (high level)
It builds on the out-of-tree Multikernel work, where several independent kernels share one machine, each owning its own CPUs, memory and devices. Kmorph boots a “successor” kernel ahead of time on a CPU or two. If the running kernel panics or hangs, the successor fences it off, takes over its devices and network identity, can optionally save a kdump-compatible vmcore, then grabs the remaining CPUs and memory.
My take
Very cool idea, but it doesn’t work on mainline Linux. It needs the Multikernel patches, and nobody knows if or when those will land. File it under “watch,” not “deploy.”
God Bless, and Use the Source!
