We used to STONITH (with an APC network power switch) over serial. It didn't really help because serial ports have really bad quality control, and lose a lot of 'packets'. :)
We ended up with dedicated serial cards, and multiple network links just so STONITH worked properly. And even then, Heartbeat was buggy as hell back then, so we'd end up in a active-active situation way too many times and we'd end up with FS corruption.
We were running Reiser on DRBD (ahh, the good old days). Had to hack the kernel a fair bit to make it all work.
Anyway, in the end, we just abandoned the automated Heartbeat failover stuff, and just used it to alert us. We manually ran the failover scripts when a human determined that there was in fact a real failure.
We ended up with dedicated serial cards, and multiple network links just so STONITH worked properly. And even then, Heartbeat was buggy as hell back then, so we'd end up in a active-active situation way too many times and we'd end up with FS corruption.
We were running Reiser on DRBD (ahh, the good old days). Had to hack the kernel a fair bit to make it all work.
Anyway, in the end, we just abandoned the automated Heartbeat failover stuff, and just used it to alert us. We manually ran the failover scripts when a human determined that there was in fact a real failure.