Re: [Engine-devel] SSH Soft Fencing
----- Original Message -----
From: "Eli Mesika" <emesika(a)redhat.com>
To: "Martin Perina" <mperina(a)redhat.com>
Cc: engine-devel(a)ovirt.org, "Yair Zaslavsky" <yzaslavs(a)redhat.com>,
"Barak Azulay" <bazulay(a)redhat.com>
Sent: Thursday, June 27, 2013 3:48:39 PM
Subject: Re: SSH Soft Fencing
----- Original Message -----
> From: "Martin Perina" <mperina(a)redhat.com>
> To: engine-devel(a)ovirt.org
> Cc: "Yair Zaslavsky" <yzaslavs(a)redhat.com>, "Barak
Azulay"
> <bazulay(a)redhat.com>, "Eli Mesika" <emesika(a)redhat.com>
> Sent: Thursday, June 27, 2013 1:51:06 PM
> Subject: SSH Soft Fencing
>
> Hi,
>
> SSH Soft Fencing is a new feature for 3.3 and it tries to restart VDSM
> using SSH connection on non responsive hosts prior to real fencing.
> More info can be found at
>
> http://www.ovirt.org/Automatic_Fencing#Automatic_Fencing_in_oVirt_3.3
>
> In current SSH Soft Fencing implementation the restart VDSM using SSH
> command is part of standard fencing implementation in
> VdsNotRespondingTreatmentCommand. But this command is executed only
> if a host has a valid PM configuration. If host doesn't have a valid
> PM configuration, the execution of the command is disabled and host
> state is change to Non Responsive.
>
> So my question are:
>
> 1) Should SSH Soft Fencing be executed on hosts without valid PM
> configuration?
I think that the answer should be yes. The vdsm restart will solve most of
problems , so why not using it whether a PM agent is defined or not.
I agree.
I would like to say that I also don't like the fact that VdsNotRespondingTreatment
extends RestartVdsCommand.
One should ask if "non responding treatment is a restart vds operation" or maybe
RestartVdsCommand is just a step in the non responding treatment (inheritance vs
containment/delegation).
I think that VdsNotRespodingTreatment should delegate the call to RestartVdsCommand as the
2nd step after issuing the Soft Fencing command.
Thoughts anyone?
>
> 2) Should VDSM restart using SSH command be reimplemented
> as standalone command to be usable also in other parts of engine?
> If 1) is true, I think it will have to be done anyway.
I agree here.
+1
>
>
> Martin Perina
>