[ClusterLabs] Notifications on changes in clustered LVM

[Ferenc Wágner]

Digimer <lists at alteeve.ca> writes:

> On 19/06/17 11:40 PM, Andrei Borzenkov wrote:
>
>> 20.06.2017 02:15, Digimer пишет:
>>
>>> On 19/06/17 06:59 PM, Ferenc Wágner wrote:
>>>
>>>> Digimer <lists at alteeve.ca> writes:
>>>>
>>>>> So we have a tool that watches for changes to clvmd by running
>>>>> pvscan/vgscan/lvscan, but this seems to be expensive and occassionally
>>>>> cause trouble.
>>>>
>>>> What kind of trouble did you experience?
>>>>
>>>>> Is there any other way to be notified or to check when something
>>>>> changes?
>>>>
>>>> LV (de)activation generates udev events (due to block devices appearing/
>>>> disappearing).  PVs too, but they don't go though clvmd.
>>>
>>> Interesting (dbus), I'll look into that.
>> 
>> udev events are sent over netlink, not D-Bus.
>
> I've not used that before. Any docs on how to listen for those events,
> by chance? If nothing off hand, don't worry, I can search.

Or just configure udev to run appropriate programs on the events you're
interested in.  Less efficient, but simpler.
-- 
Feri