Mailing List Archive

Hi,

On Tue, Oct 18, 2011 at 12:12:05PM +0200, Alberic de Pertat wrote:
> Hi,
>
>
> I am currently in the process of writing a fencing agent for VMware vCenter. After some tests, I noticed that the stonith command is turning the nodename to lowercase.

But there is already a vcenter stonith plugin (external/vcenter).

> The problem is that almost every VM in my inventory is uppercase with some mixed case too. VMware allows you to have two VM with the same name but different cases. I cannot find a proper way to deal with this as a case insensitive search through the inventory could yield more than one result.

Interesting. Not sure why would one want to have two VM's names
differ only in case.

> Looking through the stonith command source (Mercurial HEAD), I found the following in stonith.c (l. 456) :
>
>
> g_strdown(nodecopy);
>
>
> Is there a reason for this ?

Not completely sure, but most probably it was there because some
devices ignore case and produce only upper (or lower) case names.
The case should be ignored when matching node names.

Thanks,

Dejan

>
>
>
> Thanks a lot
> --
>
> Albéric de Pertat
> ADELUX
> 01 40 86 45 81

> _______________________________________________________
> Linux-HA-Dev: Linux-HA-Dev@lists.linux-ha.org
> http://lists.linux-ha.org/mailman/listinfo/linux-ha-dev
> Home Page: http://linux-ha.org/

_______________________________________________________
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On 2011-10-18 12:12, Alberic de Pertat wrote:
> Hi,
>
> I am currently in the process of writing a fencing agent for VMware
> vCenter. After some tests, I noticed that the stonith command is turning
> the nodename to lowercase.
>
> The problem is that almost every VM in my inventory is uppercase with
> some mixed case too. VMware allows you to have two VM with the same name
> but different cases.

Gah. That sounds like a great way to go insane, or drive someone else
nuts. I really wonder why on earth anyone would want to do this.

> I cannot find a proper way to deal with this as a
> case insensitive search through the inventory could yield more than one
> result.
>
> Looking through the stonith command source (Mercurial HEAD), I found the
> following in stonith.c (l. 456) :
>
> g_strdown(nodecopy);
>
> Is there a reason for this ?

I suppose Dejan will accept a patch making this configurable.

Cheers,
Florian

--
Need help with fencing?
http://www.hastexo.com/now
_______________________________________________________
Linux-HA-Dev: Linux-HA-Dev@lists.linux-ha.org
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Home Page: http://linux-ha.org/

Hi,

> > I am currently in the process of writing a fencing agent for VMware
> > vCenter. After some tests, I noticed that the stonith command is
> > turning the nodename to lowercase.
>
> But there is already a vcenter stonith plugin (external/vcenter).

Argh I should have started there.

> > The problem is that almost every VM in my inventory is uppercase
> > with some mixed case too. VMware allows you to have two VM with
> > the same name but different cases. I cannot find a proper way to
> > deal with this as a case insensitive search through the inventory
> > could yield more than one result.
>
> Interesting. Not sure why would one want to have two VM's names
> differ only in case.

I can't really say, but since it is possible, people will do eventually it.

> > Looking through the stonith command source (Mercurial HEAD), I
> > found the following in stonith.c (l. 456) :
> >
> > g_strdown(nodecopy);
> >
> > Is there a reason for this ?
>
> Not completely sure, but most probably it was there because some
> devices ignore case and produce only upper (or lower) case names.
> The case should be ignored when matching node names.

Well, I went around it by using VMware UUIDs, which are known to be unique and persistent, so the problem is solved for me but may arise again later.


I'm attaching what I did for reference. If I can find time to do it, I'll try to merge this (UUID support) with the vcenter agent.


Thanks to all.
--
Albéric de Pertat
ADELUX
01 40 86 45 81

On 2011-10-18T12:12:05, Alberic de Pertat <alberic.depertat@adelux.fr> wrote:

> I am currently in the process of writing a fencing agent for VMware vCenter. After some tests, I noticed that the stonith command is turning the nodename to lowercase.

Yes, that was added because host/nodenames by definition *are* case
insensitive. DNS, /etc/hosts, etc.

If you use "VM name == hostname" as a convention, even though VM names
themselves are case sensitive in VMware, you have effectively adopted a
policy that makes them case insensitive.

Names that differ just in case thus need to be considered a policy
violation; the stonith agent probably should detect and warn about this
(perhaps in the monitor?).


Regards,
Lars

--
Architect Storage/HA
SUSE LINUX Products GmbH, GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer, HRB 21284 (AG Nürnberg)
"Experience is the name everyone gives to their mistakes." -- Oscar Wilde

_______________________________________________________
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On 2011-10-18T12:40:40, Florian Haas <florian@hastexo.com> wrote:

> > g_strdown(nodecopy);
> >
> > Is there a reason for this ?
> I suppose Dejan will accept a patch making this configurable.

Please, no. We fence by hostname; hostnames are case insensitive by
definition. Plugins need to handle that.



Regards,
Lars

--
Architect Storage/HA
SUSE LINUX Products GmbH, GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer, HRB 21284 (AG Nürnberg)
"Experience is the name everyone gives to their mistakes." -- Oscar Wilde

_______________________________________________________
Linux-HA-Dev: Linux-HA-Dev@lists.linux-ha.org
http://lists.linux-ha.org/mailman/listinfo/linux-ha-dev
Home Page: http://linux-ha.org/

Hi,

On Wed, Oct 19, 2011 at 10:49:57AM +0200, Alberic de Pertat wrote:
> Hi,
>
> > > I am currently in the process of writing a fencing agent for VMware
> > > vCenter. After some tests, I noticed that the stonith command is
> > > turning the nodename to lowercase.
> >
> > But there is already a vcenter stonith plugin (external/vcenter).
>
> Argh I should have started there.
>
> > > The problem is that almost every VM in my inventory is uppercase
> > > with some mixed case too. VMware allows you to have two VM with
> > > the same name but different cases. I cannot find a proper way to
> > > deal with this as a case insensitive search through the inventory
> > > could yield more than one result.
> >
> > Interesting. Not sure why would one want to have two VM's names
> > differ only in case.
>
> I can't really say, but since it is possible, people will do eventually it.

I'd really be very reluctant to support such setups. It can only
cause headache for everybody involved.

Thanks,

Dejan

> > > Looking through the stonith command source (Mercurial HEAD), I
> > > found the following in stonith.c (l. 456) :
> > >
> > > g_strdown(nodecopy);
> > >
> > > Is there a reason for this ?
> >
> > Not completely sure, but most probably it was there because some
> > devices ignore case and produce only upper (or lower) case names.
> > The case should be ignored when matching node names.
>
> Well, I went around it by using VMware UUIDs, which are known to be unique and persistent, so the problem is solved for me but may arise again later.
>
>
> I'm attaching what I did for reference. If I can find time to do it, I'll try to merge this (UUID support) with the vcenter agent.
>
>
> Thanks to all.
> --
> Albéric de Pertat
> ADELUX
> 01 40 86 45 81


> _______________________________________________________
> Linux-HA-Dev: Linux-HA-Dev@lists.linux-ha.org
> http://lists.linux-ha.org/mailman/listinfo/linux-ha-dev
> Home Page: http://linux-ha.org/

_______________________________________________________
Linux-HA-Dev: Linux-HA-Dev@lists.linux-ha.org
http://lists.linux-ha.org/mailman/listinfo/linux-ha-dev
Home Page: http://linux-ha.org/

On 10/19/2011 04:11 AM, Lars Marowsky-Bree wrote:
> On 2011-10-18T12:40:40, Florian Haas<florian@hastexo.com> wrote:
>
>>> g_strdown(nodecopy);
>>>
>>> Is there a reason for this ?
>> I suppose Dejan will accept a patch making this configurable.
> Please, no. We fence by hostname; hostnames are case insensitive by
> definition. Plugins need to handle that.
More specifically - this patch was put in to make this work in the real
world. In the real world, host names correspond to DNS names (or you
will go crazy). DNS names are case-insensitive - and that's how it is.


--
Alan Robertson<alanr@unix.sh>

"Openness is the foundation and preservative of friendship... Let me claim from you at all times your undisguised opinions." - William Wilberforce
_______________________________________________________
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