[DRBD-user] A simple test

Ryan Steele steele at agora-net.com
Tue Jun 12 21:04:05 CEST 2007


Well, the only problem with that script is that it isn't mounting the 
drbd device, /dev/drbd0.  I assume it's supposed to, and I'm just not 
doing something correctly?  As a test, I manually mounted /dev/drbd0 on 
/home on machine A, created a test file, then unmounted /dev/drbd0 on 
machine A and executed a 'drbdadm secondary r0'.  I then went to machine 
B and made it primary and mounted /dev/drbd0 on /home there, but the 
test file I created wasn't there. 

Here's what gets me though:  when I unmounted /dev/drbd0 on machine A, 
and I executed an 'ls' on /home, the test file was still there.  I 
thought maybe the 'mount /dev/drbd0 /home' had silently failed, but I 
tested the same scenario again, and verified by running the 'mount' 
command that /dev/drbd0 was indeed mounted on /home.  I'm a bit confused 
here... any reason why the test file wouldn't disappear when I unmounted 
/dev/drbd0 on machine A?  I have a feeling when I get that figured out, 
I'll see the file on machine B when I mount it there...

Any suggestions are welcome, and here is some output that might help:


db1:/# cat /etc/drbd.conf
resource r0 {
  protocol      C;
  incon-degr-cmd "echo '!DRBD! pri on incon-degr' | wall ; sleep 60 ; 
halt -f";
  startup { wfc-timeout 0; degr-wfc-timeout     120; }
  disk { on-io-error detach; }
  syncer {
    rate        60M;
    group       1;   # sync when r2 is finished syncing.
  }
  on db1 {
    device      /dev/drbd0;
    disk        /dev/md7;
    address     192.168.101.26:7791;
    meta-disk   /dev/md1 [0];
  }
  on db2 {
    device      /dev/drbd0;
    disk        /dev/md7;
    address     192.168.101.27:7791;
    meta-disk   /dev/md1 [0];
  }
}

db1:/# cat /proc/drbd
version: 0.7.24 (api:79/proto:74)
SVN Revision: 2875 build by root at abbott, 2007-06-07 13:40:33
 0: cs:Connected st:Primary/Secondary ld:Consistent
    ns:92 nr:208540048 dw:208540140 dr:6460 al:2 bm:38189 lo:0 pe:0 ua:0 
ap:0
 1: cs:Unconfigured

db2:/# cat /proc/drbd
version: 0.7.24 (api:79/proto:74)
SVN Revision: 2875 build by root at abbott, 2007-06-07 13:40:33
 0: cs:Connected st:Secondary/Primary ld:Consistent
    ns:92 nr:208540048 dw:208540140 dr:6460 al:2 bm:38189 lo:0 pe:0 ua:0 
ap:0
 1: cs:Unconfigured


Best Regards,
Ryan

Ben wrote:
> Heartbeat comes with a nice script to make this easy:
>
> /etc/ha.d/resource.d/drbddisk < drbd resource >  < start | stop >
>
> You can use this even if Heartbeat isn't running, and it's the script 
> Heartbeat will use, so if you're testing to make sure Heartbeat will 
> work, I recommend using it to test. If you want to be gentle, stop the 
> resource on the first node and then start it on the second. If you 
> want to be more paranoid, pull the plug on the first node instead of 
> stopping the resource, and verify everything is still correct.
>
> On Jun 12, 2007, at 11:33 AM, Ryan Steele wrote:
>
>> Hey folks,
>>
>> Before I get Heartbeat into the mix, I want to verify DRBD is working 
>> properly in my setup.  I have DRBD running on both boxes, and have 
>> done a --do-what-I-say primary all on the first machine.  I then 
>> mounted /dev/drbd0 on /home on the first machine and put a little 
>> test file there.
>>
>> Now, I want to verify that I can mount /dev/drbd0 on /home on the 
>> second machine and see the little test file there.  What is the best 
>> way to go about doing so?  Thanks for any advice.
>>
>> By the way, /proc/drbd says things are consistent, so I think as long 
>> as I can verify what I said above, I should be ready to introduce 
>> Heartbeat.  Thanks again!
>>
>> Best Regards,
>> Ryan
>>
>> _______________________________________________
>> drbd-user mailing list
>> drbd-user at lists.linbit.com
>> http://lists.linbit.com/mailman/listinfo/drbd-user
>




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