[Drbd-dev] howto enable auto-promote

[Drbd-dev] howto enable auto-promote

[Dietmar Maurer]

I am trying to live migrate a kvm based VM which uses a 
drbd9 image created with drbdmanage. But I get the 
following error:

[ 7268.069023] drbd vm-100-disk-1: Auto-promote failed: Multiple primaries not
allowed by config

So how can I enable the auto-promote feature?

Re: [Drbd-dev] howto enable auto-promote

[Roland Kammerer]

On Wed, May 20, 2015 at 12:41:08PM +0200, Dietmar Maurer wrote:
> I am trying to live migrate a kvm based VM which uses a 
> drbd9 image created with drbdmanage. But I get the 
> following error:
> 
> [ 7268.069023] drbd vm-100-disk-1: Auto-promote failed: Multiple primaries not
> allowed by config
> 
> So how can I enable the auto-promote feature?

Auto-promote is enabled. As you can see it failed, and it can only fail
if it was enabled... Your problem is the "multiple primaries" thingy.
Please tell us which drbdmanage commands you executed. The granularity
of "trying to live migrate" is a bit too coarse to reproduce the issue.
At least for me.

Regards, rck

Re: [Drbd-dev] howto enable auto-promote

[Dietmar Maurer]

> Auto-promote is enabled. As you can see it failed, and it can only fail
> if it was enabled... Your problem is the "multiple primaries" thingy.
> Please tell us which drbdmanage commands you executed. 

What commands? The idea is that 'auto-promote' works without any commands.
So I just start the kvm VM on the second node, which tries to open the device.

So I tried to enable allow-two-primaries somehow. Adding it 
to /etc/drbd.d/global_common.conf did not help. Then I tried:

# drbdadm net-options --allow-two-primaries=yes vm-100-disk-1

on each node, and it seems to work now.

So where is the right place to set allow-two-primaries for 
volumes managed by drbdmanage? 

And why is that disabled by default? 

Re: [Drbd-dev] howto enable auto-promote

[Roland Kammerer]

On Wed, May 20, 2015 at 02:25:41PM +0200, Dietmar Maurer wrote:
> 
> > Auto-promote is enabled. As you can see it failed, and it can only fail
> > if it was enabled... Your problem is the "multiple primaries" thingy.
> > Please tell us which drbdmanage commands you executed. 
> 
> What commands? The idea is that 'auto-promote' works without any commands.
> So I just start the kvm VM on the second node, which tries to open the device.
> 
> So I tried to enable allow-two-primaries somehow. Adding it 
> to /etc/drbd.d/global_common.conf did not help. 

You probably forgot to "drbdadm adjust"...

> Then I tried:
> 
> # drbdadm net-options --allow-two-primaries=yes vm-100-disk-1
> 
> on each node, and it seems to work now.
> 
> So where is the right place to set allow-two-primaries for 
> volumes managed by drbdmanage? 

Passing these "generic drbd options" to drbdmanage is work in progress.
I expect it to be finished for the next release. 

> And why is that disabled by default? 
> 

Oh, because you really really have to know if two primiaries are a good
idea. Allowing multiple primaries is definitely nothing that should be
enabled by default.

Regards, rck

Again: Please no TO/CC, and please ask such questions on drbd-user.