mjhjmtu

I use wmware workstation to run two virtual machines with OpenVZ 2.6.32-042stab108.2 installed on top on CentOS 6.6. I have created another primary partition, /dev/sda4, to configure it as drbd resource. I also created a filsystem on it. The second machine is actually created using the virtual disk of the first one, with changed hostname and eth0 ip address. The drbd configuration file is this:

global usage-count no; 
common syncer rate 100M; 
resource r0 
 protocol C; 
 startup 
 wfc-timeout 15; 
 degr-wfc-timeout 60; 
 
 net 
 cram-hmac-alg sha1; 
 shared-secret "password"; 
 
 on primary 
 device /dev/drbd0; 
 disk /dev/sda4; 
 address 192.168.18.10:7788; 
 meta-disk internal; 
 
 on secondary 
 device /dev/drbd0; 
 disk /dev/sda4; 
 address 192.168.18.20:7788; 
 meta-disk internal; 
 

After creating the resource with drbdadm create-md r0, when I enter service drbd start, I get:

Failure: (127) Device minor not allocated.

The output of drbdadm dump all might be helpful:

[root@primary ~]# drbdadm dump all
# /etc/drbd.conf
# resource r0 on primary: not ignored, not stacked
resource r0 
 protocol C;
 on primary 
 device /dev/drbd0 minor 0;
 disk /dev/sda4;
 address ipv4 192.168.18.10:7788;
 meta-disk internal;
 
 on secondary 
 device /dev/drbd0 minor 0;
 disk /dev/sda4;
 address ipv4 192.168.18.20:7788;
 meta-disk internal;
 
 net 
 cram-hmac-alg sha1;
 shared-secret danuts;
 
 startup 
 wfc-timeout 15;
 degr-wfc-timeout 60;
 

What is causing this error and how can it be mitigated? Thanks!

I just had the same error , it appeared that IP address for the second node was not reachable.
First i checked the service status:

systemctl status drbd.service
â drbd.service - DRBD -- please disable. Unless you are NOT using a cluster manager.
 Loaded: loaded (/usr/lib/systemd/system/drbd.service; disabled; vendor preset: disabled)
 Active: failed (Result: exit-code) since mar. 2018-04-10 16:21:49 CEST; 5s ago
 Process: 3347 ExecStart=/lib/drbd/drbd start (code=exited, status=20)
 Main PID: 3347 (code=exited, status=20)

avril 10 16:21:49 GROESSLTCL0B systemd[1]: Starting DRBD -- please disable. Unless you are NOT using a cluster manager....
avril 10 16:21:49 GROESSLTCL0B drbd[3347]: Starting DRBD resources: drbd.d/r0.res:20: in resource r0, on GROESSLTCL0B:
avril 10 16:21:49 GROESSLTCL0B drbd[3347]: IP 192.168.254.2 not found on this host.
avril 10 16:21:49 GROESSLTCL0B systemd[1]: drbd.service: main process exited, code=exited, status=20/n/a
avril 10 16:21:49 GROESSLTCL0B systemd[1]: Failed to start DRBD -- please disable. Unless you are NOT using a cluster manager..
avril 10 16:21:49 GROESSLTCL0B systemd[1]: Unit drbd.service entered failed state.
avril 10 16:21:49 GROESSLTCL0B systemd[1]: drbd.service failed.

So i fixed the IP of the second node in r0.res , the new content is as following:

resource r0 
 protocol "C";

 net 
 allow-two-primaries;
 after-sb-0pri discard-zero-changes;
 after-sb-1pri discard-secondary;
 after-sb-2pri disconnect;
 
 on GROESSLTCL0A 
 device /dev/drbd0;
 disk /dev/sdb;
 address 163.104.8.108:7789;
 meta-disk internal;
 

 on GROESSLTCL0B 
 device /dev/drbd0;
 disk /dev/sdb;
 address 163.104.8.107:7789;
 meta-disk internal;
 

Then i recreated the resource:

drbdadm create-md r0

after that i restarted drbd service and all was working as expected.