[Linux-HA] cman+pacemaker+dual-primary drbd does not promote

[William Seligman]

On Tue, 31 Jan 2012 00:36:23 Arnold Krille wrote:

> On Tuesday 31 January 2012 00:12:52 emmanuel segura wrote:

>> But if you wanna implement dual primary i think you don't nee promote for
>> your drbd
>> Try to use clone without master/slave

> At least when you use the linbit-ra, using it without a master-clone will give 
> you one(!) slave only. When you use a normal clone with two clones, you will 
> get two slaves. The RA only goes primary on "promote", that is when its in 
> master-state. => You need a master-clone of two clones with 1-2 masters to use 
> drbd in the cluster.

If I understand Emmanual's suggestion: The only way I know how to implement this
is to create a simple clone group with lsb::drbd instead of Linbit's drbd
resource, and put "become-primary-on" for both my nodes in drbd.conf.

This might work in the short term, but I think it's risky in the long term. For
example: Something goes wrong and node A stoniths node B. I bring node B back
up, disabling cman+pacemaker before I do so, and want to re-sync node B's DRBD
partition with A. If I'm stupid (occupational hazard), I won't remember to edit
drbd.conf before I do this, node B will automatically try to become primary, and
probably get stonith'ed again.


Arnold: I thought that was what I was doing with these statements:

primitive AdminDrbd ocf:linbit:drbd \
	params drbd_resource="admin" \
	op monitor interval="60s" role="Master" \
	op stop interval="0" timeout="320" \
	op start interval="0" timeout="240"

ms AdminClone AdminDrbd \
	meta master-max="2" master-node-max="1" clone-max="2" clone-node-max="1"


That is, master-max="2" means to promote two instances to master. Did I get it
wrong?
-- 
Bill Seligman             | Phone: (914) 591-2823
Nevis Labs, Columbia Univ | mailto://seligman@nevis.columbia.edu
PO Box 137                |
Irvington NY 10533 USA    | http://www.nevis.columbia.edu/~seligman/

-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 4497 bytes
Desc: S/MIME Cryptographic Signature
Url : http://lists.linux-ha.org/pipermail/linux-ha/attachments/20120131/212da214/attachment.bin