Topic: HA Configuration - DRDB Problem

[Charles Noel]

Hello,

I am configuring a pair of SME servers as HA devices.  I'm at step 8 of the process, and all appeared to be running well unitl I noticed that both devices show the following when I issue the cat /proc/drbd command:

0: cs:Connected st:Secondary/Secondary ns:0 nr:0 dw:0 gc:1,1,1

Neither device assumes a Primary role for the RAID device.

Doing a df -h on either system does not list the RAID drive as being available.

The RAID mirror appears to be non-exisatant; however, I find no errors in any logs or startup scripts.

Anyone have an idea what I might have missed?

Thanks,

Charles Noel

[guestHH]

Hi Charles,

> 0: cs:Connected st:Secondary/Secondary ns:0 nr:0 dw:0 gc:1,1,1

Did you check your drbd config files and setup? Maybe you can try to see what happens if you use the drbdsetup command (option --help for more info or man)
With drbdsetup you can start the RAID process manually instead of autmatic with the scripts. This way you can proceed step by step and 'debug' the process.

> Neither device assumes a Primary role for the RAID device.
>Doing a df -h on either system does not list the RAID drive as being available.

The RAID drive is only mounted _and_ visable if one of the pair is primary.

>The RAID mirror appears to be non-exisatant; however, I find no errors in any logs or startup scripts.

Only heartbeat produces seperate logfiles. drbd put it's messages in /var/log/messages.

Since this is a specific drbd question, you may want to search drbd's mailinglist archive at:
http://sourceforge.net/mailarchive/forum.php?forum_id=6513

Hope it helps a little.

Regards,
guestHH

[Charles Noel]

Okay, I reviewed the documentation at the drbd site completed the how-to configuration.

The drives completely sync, but continue to not be available to the system.

Running cat /proc/drbd shows the drives running properly, but running df -h does not list /dev/hdc1 in the listing of drives available to the system.

My question is:

Do I need to add an entry for /dev/hdc1 in fstab and create a mount point for it?

Thanks again,

Charles

[guestHH]

Hi Charles,

Yes, you do have to add an entry in fstab, but not for the actual hdc1 but for the device drive nb0.

Step 9 says:

Integrating the RAID-1 with heartbeat is the next thing to do.
We have to tell drbd that we want the RAID-1 to be controlled by the secondary node upon fail-over/back and visa versa. (Make it work parallel with heartbeat)

Since we setup our RAID-1 with 1 resource called drbd0 (see drbd.conf) we have to change the /etc/ha.d/haresources file. (more resources are possible for each partition you make on the RAID-1)

Current entry in /etc/haresources:
Goliath 192.168.1.210/24/eth0 smb

Change it to:
Goliath 192.168.1.210/24/eth0 datadisk::drbd0 smb

The script datadisk is located at /etc/ha.d/resource.d and will take care of switching drbd state. Heartbeat will search for the script in /etc/rc.d/init.d directory. If it’s not there it will look for it in /etc/ha.d/resource.d

So the above line tells heartbeat to use the script ‘datadisk’ with argument ‘drbd0’ (::=argument separator)

Now we want to make our RAID-1 mountable at boot time. We have to edit the /etc/fstab file. Add the following line to /etc/fstab:

/dev/nb0   /home/e-smith/files/ibays/data/files     ext2    noauto  0 0

Do NOT actually mount on boot time, the datadisk script together with the noauto option will take care of this.

Regards,
RequestedDeletion

ps. Which version of the howto are you using?

[Charles Noel]

Hello RequestedDeletion,

I'm using the 1.2.1 version of the How-To.

I have reviewed all entries in drbd.conf,  /etc/haresources & /etc/fstab character-by-character - and find no deviation from the How-To.

I will review all associated files again, and will let you know if I find anything.

Thanks for your assistance.

Charles