kdump Archives - AWS Managed Services by Anchor

Bugfixing the in-kernel megaraid_sas driver, from crash to patch

By | Technical | 2 Comments

Today we bring you a technical writeup for a bug that one of our sysadmins, Michael Chapman, found a little while ago. This was causing KVM hosts to mysteriously keel over and die, obviously causing an outage for all VM guests running on the system. The bug was eventually traced to the megaraid_sas driver and the patch has made it to the kernel as of version 3.3. As you can imagine, not losing a big stack of customer VMs at a time, possibly at any hour of the day, is a pretty exciting prospect. This will be a very tech-heavy post but if you’ve ever gone digging into kernelspace (as a coder, or someone on the ops side of the fence) we hope it’ll pique your interest. We’ll talk about…

Read More