[DRBD-user] Cannot synchronize stacked device to backup server with DRBD9

[Artur Kaszuba]

W dniu 13.06.2018 o 11:58, Robert Altnoeder pisze:
> On 06/12/2018 10:18 AM, Artur Kaszuba wrote:
>> Im trying to create stacked device with drbd9
> 
> The idea behind DRBD 9.x is that you don't need a stacked device,
> instead you can just connect all 3 nodes directly:
> 
> resource system-test
> {
<cut>
> }
> 
Hi Robert, thx for answer.

I know about 3 node solution and i have used it for some time (from 
~9.0.8), but i had problems with stability and decided to change 
configuration to stacked configuration, with hope it will work more 
stable. As a last solution i will downgrade to drbd8 where never had any 
problems with stability, but i would like to stay with 9 and after some 
time switch again to 3 node config.

By stability i mean such situation:
- last version of drbd9 (9.0.14)
- kernel 4.13.0-43-generic on Ubuntu 16.04
- high disk usage/IO on drbd devices
- 3 node configuration
- random system crash on "drbdam disconnect/connect" command
When i disable one node everything works without problems and 
disconnect/connect works perfectly. Before 9.0.14 i dont had such 
crashes, but had other which are fixed now. Unfortunately i cannot wait 
for next fix, i need stable environment.

>> IMO it not support correctly stacked devices.
> 
> See above, stacking has been replaced with direct connections.
> 
> Best regards,
> 

I prefer to use stacking configuration, even when it is deprecated in 
DRBD9. I decided to write this post because stacked configuration is 
still described in documentation and should work? Unfortunately for now 
it is not possible to create such configuration or i missed something :/

Regards

-- 
Artur Kaszuba