[ClusterLabs] Antw: [EXT] Re: Which fence agent is needed for an Apache web server cluster?

[Ulrich Windl]

>>> Reid Wahl <nwahl at redhat.com> schrieb am 28.03.2021 um 00:42 in Nachricht
<CAPiuu9_R3dzDGimzasrYRSjEqj06a+fmT+Eg4SauwrDdDOijNg at mail.gmail.com>:
> On Sat, Mar 27, 2021 at 4:28 PM Strahil Nikolov <hunter86_bg at yahoo.com>
> wrote:
> 
>> I had to tune the fence_ipmi recently on some older HPE blades. The
>> default settings were working, but also returning some output about
>> problems negotiating the cypher.
>> As that output could make future version of the fence agent go wild, I
>> tested several options untill no errors are reported. Maybe the cypher flag
>> was different, but I think it was '-c'. If I'm wrong , the author of this
>> thread can check the man page .
>>
>> Yes -> 'HandlePowerKey=ignore' . I have never expected ipmi to try
>> graceful shutdown when I tell it to 'press and hold' or 'cold boot', yet I
>> never checked the code of fence_ipmi.

I think for HP you actually have four options (in iLO at least):
1) Power Cycle (hardest version of a reset)
2) Reset (the traditional "reset" button)
3) Pressand Hold the Power button: Most likely it wil lsend an ACPI power event first, tehmn within a very few seconds tun off power
4) Press (ACPI) Power Button shortly: deliver an ACPI event the OS may handle

Maybe you even have a 5th option to send an NMI (I think the hardware watchdog does that) (which could cause a kernelpanic with dump, or just be ignored)

However I don't know how much of it is available through IPMI.
On an old DL380 G7 I get:
# ipmitool power
chassis power Commands: status, on, off, cycle, reset, diag, soft
# ipmitool chassis power
chassis power Commands: status, on, off, cycle, reset, diag, soft

Regards,
Ulrich

>>
> 
> fence_ipmilan uses ipmitool to send a poweroff signal. The iLO then sends a
> virtual power button press, which IIRC goes through ACPI. By default on
> RHEL 7 and above, if the system is responsive, systemd-logind handles a
> power key press by initiating a graceful shutdown. You have to disable it
> from handling the power key press so if you want hard-power-off behavior.
> 
> 
>> With triple sbd , I mean sbd with 3 block devices.
>>
>> Best Regards,
>> Strahil Nikolov
>>
>> On Sat, Mar 27, 2021 at 23:15, Reid Wahl
>> <nwahl at redhat.com> wrote:
>>
>>
>> On Saturday, March 27, 2021, Strahil Nikolov <hunter86_bg at yahoo.com>
>> wrote:
>> > My notes:
>> > - ilo ssh fence mechanism is crappy due to ilo itself, try to avoid if
>> possible
>>
>> It has been unreliable in my experience.
>>
>> > - fence_ipmi requires some tunings (-c flag) and also to disable power
>> button from the system
>>
>> I've rarely, perhaps never, seen a customer have to tune the -c flag.
>>
>> By disabling the power button, do you mean setting HandlePowerKey=ignore
>> in logind.conf? That's not specific to fence_ipmilan, to be clear.
>>
>> > - triple 'sbd' is quite reliable.My previous company was using 'softdog'
>> kernel module for a watchdog device and it never failed us. Yet, it's just
>> a kernel module (no hardware required) and thus RH do not support such
>> setup.
>>
>> What do you mean by triple sbd? Correct that RH doesn't support using
>> softdog as an sbd watchdog device. It was determined that it's not reliable
>> in all situations. It's probably fine much of the time, and I'm glad you
>> had a smooth experience with it.
>> >
>> > On Sat, Mar 27, 2021 at 22:15, Reid Wahl
>> > <nwahl at redhat.com> wrote:
>> > _______________________________________________
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>>
>> >
>>
>> --
>> Regards,
>>
>>
>> Reid Wahl, RHCA
>> Senior Software Maintenance Engineer, Red Hat
>> CEE - Platform Support Delivery - ClusterHA
>>
>>
> 
> -- 
> Regards,
> 
> Reid Wahl, RHCA
> Senior Software Maintenance Engineer, Red Hat
> CEE - Platform Support Delivery - ClusterHA