<div style="line-height:1.7;color:#000000;font-size:14px;font-family:Arial"><div>Hi Joel,</div><div>Thanks for the reply. I have a 3 node cluster and all 3 nodes running with DRBD9.0: Primary node is</div><div>node-1, and Secondary nodes are node-2 and node-3, quorum is configured as 2.</div><div><br /></div><div>After some more investigation, I found the root cause of this problem we met is that NEW_CUR_UUID</div><div>will clear whether a new uuid was actually generated in make_new_current_uuid.</div><div><br /></div><div>You can reproduce this problem on DRBD9.0 through the following steps:</div><div>(1) network failure on node-2</div><div>(2) network failure on node-3</div><div>(3) write on node-1(will suspend since quorum loss)</div><div>(4) node-2 network recovery</div><div>(5) node-3 network recovery</div><div>you will find that data on node-3 is inconsistent with two other nodes.</div><div><br /></div><div>I also find this problem is not exist in DRBD9.1 since the code of inc_ap_bio_cond</div><div>in DRBD9.1 is different from that in DRBD9.0, so i have sent a patch for this bug in</div><div>DRBD9.0:<br /></div><div style="position:relative;zoom:1"></div><div>https://lists.linbit.com/pipermail/drbd-dev/2022-April/006576.html<br /></div><div> So you can go to review my new patch directly.</div><div>By the way, have you focused on DRBD9.1 and is there a stable verison of it?</div><div>Thanks,</div><div>Xu<br /></div><pre>From: Joel Colledge <joel.colledge@linbit.com>
Date: 2022-04-07 18:48:12
To: Rui Xu <rui.xu@easystack.cn>
Cc: Philipp Reisner <philipp.reisner@linbit.com>,drbd-dev@lists.linbit.com,dongsheng.yang@easystack.cn
Subject: Re: [PATCH] drbd: create new uuid even we dont have quorum>Hi,
>
>When quorum is configured, we expect not to have split-brain
>situations. Hence it is important that we do not generate new UUIDs
>until they are definitely necessary. When we do not have quorum, no
>writes should complete, so we do not need to generate a new UUID. We
>may need to generate one before we regain quorum instead.
>
>That said, there have been various bugs in the implementation. Try to
>reproduce your issue with the latest drbd-9.1. If it can still be
>reproduced, then describe the exact reproduction steps and we can
>discuss the appropriate fix.
>
>Best regards,
>Joel
</pre></div><br>