Re: [ClusterLabs] Notifications on changes in clustered LVM

2017-06-23 Thread Jan Pokorný 
On 20/06/17 10:59 +0200, Ferenc Wágner wrote:
> Digimer  writes:
> 
>> On 19/06/17 11:40 PM, Andrei Borzenkov wrote:
>>> 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.

FYI, in the past, I've experimented with ordinary-user-access based
filtering of the events as obtained from "udevadm monitor", which used
to work happily out of the box:
"https://fedorapeople.org/cgit/jpokorny/public_git/uudev.git/
(in that example, I was running a custom script when the particular
keyboard was attached, I believe).

It's rather a poor man's solution, but the advantage is that it
doesn't require root's privileges for anything, and may suffice for
some use cases (not sure if for yours, Digimer, as well).

-- 
Jan (Poki)


pgpHyRnI7zS_N.pgp
Description: PGP signature
___
Users mailing list: Users@clusterlabs.org
http://lists.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

Re: [ClusterLabs] Notifications on changes in clustered LVM

2017-06-20 Thread Ferenc Wágner 
Digimer  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  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

___
Users mailing list: Users@clusterlabs.org
http://lists.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

Re: [ClusterLabs] Notifications on changes in clustered LVM

2017-06-19 Thread Digimer 
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  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.

-- 
Digimer
Papers and Projects: https://alteeve.com/w/
"I am, somehow, less interested in the weight and convolutions of
Einstein’s brain than in the near certainty that people of equal talent
have lived and died in cotton fields and sweatshops." - Stephen Jay Gould

___
Users mailing list: Users@clusterlabs.org
http://lists.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

Re: [ClusterLabs] Notifications on changes in clustered LVM

2017-06-19 Thread Andrei Borzenkov 
20.06.2017 02:15, Digimer пишет:
> On 19/06/17 06:59 PM, Ferenc Wágner wrote:
>> Digimer  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.


___
Users mailing list: Users@clusterlabs.org
http://lists.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

Re: [ClusterLabs] Notifications on changes in clustered LVM

2017-06-19 Thread Digimer 
On 19/06/17 06:59 PM, Ferenc Wágner wrote:
> Digimer  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.

As to what happens; Total lock up of LVM until a node is fenced out of
the cluster. I have an open RHBZ if you are curious;

https://bugzilla.redhat.com/show_bug.cgi?id=1452894

-- 
Digimer
Papers and Projects: https://alteeve.com/w/
"I am, somehow, less interested in the weight and convolutions of
Einstein’s brain than in the near certainty that people of equal talent
have lived and died in cotton fields and sweatshops." - Stephen Jay Gould

___
Users mailing list: Users@clusterlabs.org
http://lists.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

Re: [ClusterLabs] Notifications on changes in clustered LVM

2017-06-19 Thread Ferenc Wágner 
Digimer  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.
-- 
Regards,
Feri

___
Users mailing list: Users@clusterlabs.org
http://lists.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

[ClusterLabs] Notifications on changes in clustered LVM

2017-06-19 Thread Digimer 
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. Is there any other way to be notified or to check when
something changes?

cheers

-- 
Digimer
Papers and Projects: https://alteeve.com/w/
"I am, somehow, less interested in the weight and convolutions of
Einstein’s brain than in the near certainty that people of equal talent
have lived and died in cotton fields and sweatshops." - Stephen Jay Gould

___
Users mailing list: Users@clusterlabs.org
http://lists.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