[DRBD-user] what's the correct procedure for promoting secondary to primary (when primary is down)?

Lonni J Friedman netllama at gmail.com
Fri Sep 21 18:23:32 CEST 2012

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.

On Fri, Sep 21, 2012 at 7:51 AM, Felix Frank <ff at mpexnet.de> wrote:
> Hi,
> the scenario is really very common and requires no action aside from
> those documented everywhere.
> On 09/21/2012 04:17 PM, Lonni J Friedman wrote:
>> I'm trying to do a proof of concept, in which I was attempting to
>> synthetically simulate the failure of the primary.   I did this by
>> bringing down the network interface on the primary.  Prior to doing
>> that, drbd-overview reported everything as being in sync
>> (UpToDate/UpToDate).
> Then after pulling the plug - what does drbd-overview tell you now?
> What's your local disk state (on the secondary)?
> I suspect it's no longer UpToDate. If you wonder why it's not, please
> examine the kernel logs on your secondary. All state changes are usually
> logged and explained. Fell free to share them if they are not helpful on
> their own.

I suspect you're right.  I think what happened is that I was fumbling
around through different drbdadm commands in an attempt to find the
right combination & ordering to get this working, and likely made a
huge mess of things.

This time, I took special care to note exactly what I was doing, and I
believe that I've found a series of steps that does the right thing:
drbdadm primary r0	# run on secondary to promote to primary
drbdadm secondary r0	# run on (original) primary to demote to secondary
drbdadm invalidate r0	# run on (new) secondary
drbdadm connect r0	# run on (new) secondary

At least, that has accomplished what I was trying to do all along, and
everything currently reports as UpToDate/UpToDate.

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