https://jira.whamcloud.com This file is an XML representation of an issue en-us 9.4.14 940014 05-12-2023 https://jira.whamcloud.com/browse/LUDOC-31 Lustre Documentation <p><tt>--servicenode</tt> is not documented in the manual</p> LUDOC-31

servicenode is not documented

Improvement Minor Closed Fixed Jessica A. Popp Richard Henwood Wed, 21 Dec 2011 12:35:51 +0000 Tue, 27 Nov 2012 07:19:27 +0000 Wed, 1 Feb 2012 14:48:22 +0000 0 0 <p>I have just had a chat with Brian on this topic, the conversation went as follows:</p> <p><b>B</b> historically, when one formats a target with a failnode and then registers it, the node it was registered from and the fail node are both written as locations for the target.<br/> when you use &#45;&#45;servicenode the node you register from is no longer listed as a service node but the listed --servicenodes are.<br/> <b>B</b> this makes it possible to register the target somewhere other than where you intend it to run, for example.<br/> <b>B</b> so imagine &#45;&#45;servicenode as being the merging of --failnode and (a fictitious and implied) --register-from-node parameter. if that makes sense.<br/> <b>B</b> imho, &#45;&#45;servicenode is superior and less confusing than the old implict +&#45;&#45;failnode behaviour.<br/> <b>B</b> since it makes absolutely clear which nodes will be service nodes and doesn't hide one of them as the node being registered from.<br/> <b>B</b> and it also doesn't require a specific one (or any, iiuc) of the service nodes to be up in order to register the target<br/> <b>Me</b> what is a service node?<br/> <b>B</b> a node that provides service for the target<br/> <b>B</b> i.e. an OSS or MDS<br/> <b>Me</b> is Active-Active failover an example of when you would want to register an target without a service node?<br/> <b>B</b> so normally if you have two nodes (A and B) for a target you do:</p> <div class="code panel" style="border-width: 1px;"><div class="codeContent panelContent"> <pre class="code-java">A # mkfs.lustre ... --failnode B /dev/sda A # mount -t lustre /dev/sda /mnt with service node you (can) <span class="code-keyword">do</span>: C # mkfs.lustre ... --servicenode A --servicenode B C # mount -t lustre /dev/sda /mnt </pre> </div></div> <p><b>B</b> and nodes A and B will be configured as the nodes that hosts go to for that target<br/> <b>J</b> the service node option is just a way to control what nids are registered to the mgs</p> <p>manual update tracking at <a href="http://review.whamcloud.com/1904" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/1904</a></p> <p>Excellent! Thanks for getting on this so quickly!</p> <p>Bobijam's manual update has landed.</p> Development Rank 1|hzvl3r: Rank (Obsolete) 7180