On 1 Mar 2018, at 15:37, Joe Jones wrote: > yes we use pfsync. Yesterday we tried with pfsync switched off, the > box still locked up but this time without a panic. > > We make the DIOCRADDADDRS ioctl on the master and the backup (we use > CARPed pairs). > Interesting. It might be related to pfsync. Is is the master that panics or the backup? Or both? Regards, Kristof