The head node name of the DPM is stored inside the Surl of the file and in the LFC and within DDM within ATLAS, probably inside Alien.... A DNS alias change is probably the best recommendation. If this is not possible, then there are probably methods that can be done ( copying of all precious data, wiping you DPM/LFC/VO tools clean and starting afresh, though this is the WMD option.)
Brian
-----Original Message-----
From: GRIDPP2: Deployment and support of SRM and local storage management [mailto:[log in to unmask]] On Behalf Of Sam Skipsey
Sent: 17 May 2010 09:13
To: [log in to unmask]
Subject: Re: Moving A DPM Head Node
On 14 May 2010 17:04, Chris Curtis <[log in to unmask]> wrote:
> Hi -
>
> Our DPM head node services (albeit the "Golden Release"!) are
> currently running on an old SL4 32 bit machine, and I would like to
> move them to an
> SL5 64 bit machine.
>
> I am confident that I can configure the new machine to be a head node,
> but I don't know what to do about the fact that the new head node
> will, unavoidably, have a new IP address and hostname.
While I understand how a new IP might be unavoidable, I'm less convinced that it shouldn't be possible to finagle a bit of hostname switching in your University DNS. The DPM db does store the name of the DPM head node in one or two places, and its easier to migrate if these remain constant (not least because it means your MySQL access permissions are the same).
>
> My first question is will this have an effect on exiting data in
> existing pool nodes? The DPM mysql server is already hosted on a
> separate machine, which is not changing.
>
No. That'll all be fine.
> Secondly, the existing head node has some old RAIDs hanging directly
> off it, so I would like to convert it into a normal pool node. How
> should this be done? My plan so far consists of 1) draining the RAIDS
> onto an existing pool node 2) installing the new head node 3)
> configuring the old head node to be a pool node 4) drain the files
> back. Are there any obvious pitfalls here?
>
Nothing I can think off: except, you can't do targeted drains.
(That is: you can *dpm-drain* from a filesystem, but you can't control precisely where those files go.)
> Finally, what are the implications for changing the SE name from ATLAS'
> point of view? Presumeably the ToA will have to change? Who would
> have to know about this?
Another reason to try to keep the old SE hostname if possible (ips of course, don't matter).
Wahid's covered the rest of this, though.
Sam
>
> Cheers,
>
> Chris
>
>
>
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