[ClusterLabs] VG activation on Active/Passive

[Dejan Muhamedagic]

Hi,

On Mon, Aug 31, 2015 at 03:28:28PM +0300, Andrei Borzenkov wrote:
> 
> 
> Отправлено с iPhone
> 
> > 29 авг. 2015 г., в 21:51, Jorge Fábregas <jorge.fabregas at gmail.com> написал(а):
> > 
> >> On 08/29/2015 02:37 PM, Digimer wrote:
> >> No need for clustered LVM, only the active node should see the PV. When
> >> the passive takes over, after connecting to the PV, it should do a
> >> pvscan -> vgscan -> lvscan before mounting the FS on the LV.
> >> 
> >> Keep you cluster simple; remove everything not needed.
> > 
> > Hi Digimer,
> > 
> > It would be great if my cluster could communicate with the storage-array
> > to make it "present" or "unpresent" LUNs based on the cluster conditions
> > but I'm afraid that's not possible :)  
> 
> Just use SCSI-3 persistent reservations to grant exclusive access to a node that has active resources.
> 
> > So yes, these are LUNs that are
> > visible on both nodes.
> > 
> > I'm the one who asked you something regarding cLVM on IRC the other day
> > (one of the many times you have helped me there) and I decided to go the
> > cLVM/DLM route (because the LUNs are seen on both nodes)
> 
> I do not quite understand what it gains you. How having LVs on both nodes is different from having underlying raw devices?

There is not much use of a raw device if you cannot access it
with LVM tools as part of a volume group.

Thanks,

Dejan

> 
> 
> > but now I have
> > my issues with this VG activation.
> > 
> > Thanks.
> > 
> > Regards,
> > Jorge
> > 
> > 
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