[DRBD-user] Problems configuring an active/active setup

Lorenzo Milesi lorenzo.milesi at yetopen.it
Thu Jun 12 14:34:40 CEST 2008


Hi

I'm having problems configuring an active/active setup. I've done
several searches, leading only to few howtos and documentations, very
similar each other.

The main problem is that I cannot handle split-brain in case of net
failure. I think I've correctly setup both drbd and heartbeat to do so,
but drbd always remains in an inconsistent state after sb.
In case of sb I can have a master node which can be the syncsource, so
I've set after-sb-0pri accordingly.

And I've also another big problem, as in case of short network outage
BOTH nodes gets stonith'ed! What am I doing wrong? Both nodes' drbd.conf
must be identical, right?
They're connected only via network.

Any help really appreciated. Thanks.


These are the relevant parts of drbd.conf:
resource r0 {
  protocol C;
  handlers {
    pri-on-incon-degr "echo o > /proc/sysrq-trigger ; halt -f";
    pri-lost-after-sb "echo o > /proc/sysrq-trigger ; halt -f";
    local-io-error "echo o > /proc/sysrq-trigger ; halt -f";
    outdate-peer "/usr/lib/heartbeat/drbd-peer-outdater";
    
    pri-lost "echo pri-lost. Have a look at the log files. | mail -s
'DRBD Alert' dontspamme at spamme.com";

    # Notify someone in case DRBD split brained.
    split-brain "echo split-brain. drbdadm -- --discard-my-data connect
$DRBD_RESOURCE ? | mail -s 'DRBD Alert' dontspamme at spamme.com";
  }
  startup {
    degr-wfc-timeout 120;
    wfc-timeout 120;
    become-primary-on both;
  }

  disk {
    on-io-error   detach;
    fencing       resource-and-stonith;
  }

  net {
    allow-two-primaries;
    after-sb-0pri discard-node-node2;
    after-sb-1pri discard-secondary;
    after-sb-2pri disconnect;
    rr-conflict disconnect;

  syncer {
    rate 50M;
    al-extents 257;
  }

omitting the "on" statements as they're fine.

this is the heartbeat's cib.xml, for stonith:
<cib generated="true" admin_epoch="0" have_quorum="1" num_peers="2"
cib_feature_revision="1.3" ccm_transition="1" ignore_dtd="false"
crm_feature_set="2.1" epoch="795"
dc_uuid="6259bf18-2678-4fe5-834f-d1e4bb63c9e8" num_updates="17"
cib-last-written="Wed Jun 11 11:01:57 2008">
   <configuration>
     <crm_config>
       <cluster_property_set id="bootstrap">
         <attributes>
           <nvpair id="bootstrap01" name="transition-idle-timeout"
value="60"/>
           <nvpair id="bootstrap02" name="default-resource-stickiness"
value="INFINITY"/>
           <nvpair id="bootstrap03"
name="default-resource-failure-stickiness" value="-500"/>
           <nvpair id="bootstrap04" name="stonith-enabled"
value="true"/>
           <nvpair id="bootstrap05" name="stonith-action"
value="reboot"/>
           <nvpair id="bootstrap06" name="symmetric-cluster"
value="true"/>
           <nvpair id="bootstrap07" name="no-quorum-policy"
value="stop"/>
           <nvpair id="bootstrap08" name="stop-orphan-resources"
value="true"/>
           <nvpair id="bootstrap09" name="stop-orphan-actions"
value="true"/>
           <nvpair id="bootstrap10" name="is-managed-default"
value="true"/>
         </attributes>
       </cluster_property_set>
       <cluster_property_set id="cib-bootstrap-options">
         <attributes>
           <nvpair id="cib-bootstrap-options-dc-version"
name="dc-version" value="0.6.4-node:
226d8e35692415c56dbd05258a85905414938ce9"/>
         </attributes>
       </cluster_property_set>
     </crm_config>
     <nodes>
       <node id="6259bf18-2678-4fe5-834f-d1e4bb63c9e8" uname="host1"
type="normal"/>
       <node id="52f4f725-21b0-49e8-b4d8-a7124637ca6f" uname="host2"
type="normal"/>
     </nodes>
     <resources>
       <clone id="stonithcloneGroup" globally_unique="false">
         <instance_attributes id="stonithcloneGroup">
           <attributes>
             <nvpair id="stonithclone01" name="clone_node_max"
value="1"/>
           </attributes>
         </instance_attributes>
         <primitive id="stonithclone" class="stonith"
type="external/ssh" provider="heartbeat">
           <operations>
             <op name="monitor" interval="5s" timeout="20s"
prereq="nothing" id="stonithclone-op01"/>
             <op name="start" timeout="20s" prereq="nothing"
id="stonithclone-op02"/>
           </operations>
           <instance_attributes id="stonithclone">
             <attributes>
               <nvpair id="stonithclone01attr" name="hostlist"
value="host1,host2"/>
             </attributes>
           </instance_attributes>
         </primitive>
       </clone>
     </resources>
     <constraints/>
   </configuration>
</cib>

-- 

Lorenzo Milesi - lorenzo.milesi at yetopen.it

YetOpen S.r.l. - http://www.yetopen.it/
C.so E. Filiberto, 74 23900 Lecco - ITALY -
Tel 0341 220 205 - Fax 178 607 8199

GPG/PGP Key-Id: 0xE704E230 - http://keyserver.linux.it




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