On 09/05/2016 09:38 AM, Marek Grac wrote: > Hi, > > On Mon, Sep 5, 2016 at 3:46 PM, Dan Swartzendruber <dswa...@druber.com > <mailto:dswa...@druber.com>> wrote: > > ... > Marek, thanks. I have tested repeatedly (8 or so times with disk > writes in progress) with 5-7 seconds and have had no corruption. My > only issue with using power_wait here (possibly I am > misunderstanding this) is that the default action is 'reboot' which > I *think* is 'power off, then power on'. e.g. two operations to the > fencing device. The only place I need a delay though, is after the > power off operation - doing so after power on is just wasted time > that the resource is offline before the other node takes it over. > Am I misunderstanding this? Thanks! > > > You are right. Default sequence for reboot is: > > get status, power off, delay(power-wait), get status [repeat until OFF], > power on, delay(power-wait), get status [repeat until ON]. > > The power-wait was introduced because some devices respond with strange > values when they are asked too soon after power change. It was not > intended to be used in a way that you propose. Possible solutions:
I thought power-wait was intended for this situation, where the node's power supply can survive a brief outage, so a delay is needed to ensure it drains. In any case, I know people are using it for that. Are there any drawbacks to using power-wait for this purpose, even if that wasn't its original intent? Is it just that the "on" will get the delay as well? > *) Configure fence device to not use reboot but OFF, ON > Very same to the situation when there are multiple power circuits; you > have to switch them all OFF and afterwards turn them ON. FYI, no special configuration is needed for this with recent pacemaker versions. If multiple devices are listed in a topology level, pacemaker will automatically convert reboot requests into all-off-then-all-on. > *) Add a new option power-wait-off that will be used only in OFF case > (and will override power-wait). It should be quite easy to do. Just, > send us PR. > > m, _______________________________________________ Users mailing list: Users@clusterlabs.org http://clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org