Lustre discuss - Nov 2009 - OSS server

Hi,

I apologize for my lack of clarity, try to be clearer.
The scenario is:

- one server with MGS/MDS
- one server with OSS
- the OST is on SAN

If the server OSS has a hardware failure
and I must physically change the machine.
With the new machines, how can I retrieve data on the OST, located on  
SAN ?
I hope to be clear enough !!
Thanks



Ing. Stefano Elmopi
Gruppo Darco - Resp. ICT Sistemi
Via Ostiense 131/L Corpo B, 00154 Roma

cell. 3466147165
tel.  0657060500
email:stefano.elmopi at sociale.it

Il giorno 20/nov/09, alle ore 20:00, lustre-discuss-request at lists.lustre.org 
  ha scritto:
> Date: Fri, 20 Nov 2009 10:53:15 -0500
> From: "Brian J. Murrell" <Brian.Murrell at Sun.COM>
> Subject: Re: [Lustre-discuss] OSS server
> To: lustre-discuss at lists.lustre.org
> Message-ID: <1258732395.21860.30.camel at pc.interlinx.bc.ca>
> Content-Type: text/plain; charset="utf-8"
>
> On Fri, 2009-11-20 at 14:37 +0100, Stefano Elmopi wrote:
>> If I have a simple scenario with one MGS/MDS and one OSS, without
>> failover,
>> and the server OSS crash,
>
> I''m afraid "crash" is an ambiguous term in this context.
Do you mean
> the O/S panics or some equivalent event?  The solution would be to
> simply reboot the machine, no?
>
> Or do you mean that the hardware itself has broken such that you  
> need to
> replace it?  Wouldn''t you just move the disks in the old machine
to
> the
> new one and boot that so that as far as the rest of the network is
> concerned, the machine was simply rebooted?
>
>> Simply replace the server root with one that has the same IP ??
>
> Yes, I think so.  Although your scenario is not terribly clear for me.
>
> b.
>
>
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On Mon, 2009-11-30 at 11:23 +0100, Stefano Elmopi wrote:
> Hi,
Hi, 
> - one server with MGS/MDS
> - one server with OSS
> - the OST is on SAN
> 
> 
> If the server OSS has a hardware failure
> and I must physically change the machine.
If the machine boots from the network then the new system is a drop-in
replacement for the broken machine and you need to do nothing, right?

Or if the system boots from it''s own disk you would either a) put the
disk from the broken OSS into the new hardware or b) re-image the OSS
and configure it to be identical (IP address, etc.) as the machine that
died, or c) restore the system image from a backup or d) some other
reasonable facsimile/combination of the above options that results in
the new machine being a like-replacement for the broken machine.

None of this is really all that particular to Lustre though and it just
typical syadmin practises that one would follow for replacing any
machine that dies.  When your mail server dies, what do you do to
replace it such that it''s an identical (to the users) replacement? 
Same
situation for an OSS.
> With the new machines, how can I retrieve data on the OST, located on
> SAN ?
Once the new machine is configured identical to the one it''s replacing,
it will just access that OST as if nothing happened, no?
> I hope to be clear enough !!
I think you are.  I guess the not-really-particular-to-Lustre nature of
the question had me somewhat thinking that there must be something I was
missing.  I guess there was not.

b.


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