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<p class="MsoNormal">We use a site specific systemd unit which we call gpfs_fs.service that `BindsTo=gpfs.service` and `After=gpfs.service`. This service basically waits for GPFS to become active and then once active attempts to mount the required file systems.
The list of file systems is determined by our own system configuration software (e.g. puppet/cfengine/salt-stack/ansible).<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">We have also added a custom extension to gpfs.service (/usr/lib/systemd/system/gpfs.service.d/gpfs.service.conf) which adds a ExecStartPre to the IBM provided unit (we don’t want to mess with this IBM provide file). This ExecStartPre will
make sure the node has the required version of GPFS installed and do some other basic checks.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">We have other systemd controlled process then both `BindsTo` and `After` the gpfs_fs.service. This works pretty well for us.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hope that helps,<o:p></o:p></p>
<p class="MsoNormal">-Bryan<o:p></o:p></p>
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<p class="MsoNormal"><b>From:</b> gpfsug-discuss-bounces@spectrumscale.org <gpfsug-discuss-bounces@spectrumscale.org>
<b>On Behalf Of </b>Frederick Stock<br>
<b>Sent:</b> Thursday, March 14, 2019 3:17 PM<br>
<b>To:</b> gpfsug-discuss@spectrumscale.org<br>
<b>Cc:</b> gpfsug-discuss@spectrumscale.org<br>
<b>Subject:</b> Re: [gpfsug-discuss] Systemd configuration to wait for mount of SS filesystem<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">[EXTERNAL EMAIL]<o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial",sans-serif">It is not systemd based but you might want to look at the user callback feature in GPFS (mmaddcallback). There is a file system mount callback you could register.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Arial",sans-serif"><br>
</span><span style="font-size:12.0pt;font-family:"Arial",sans-serif">Fred<br>
__________________________________________________<br>
Fred Stock | IBM Pittsburgh Lab | 720-430-8821<br>
</span><a href="mailto:stockf@us.ibm.com"><span style="font-size:12.0pt;font-family:"Arial",sans-serif">stockf@us.ibm.com</span></a><span style="font-size:10.5pt;font-family:"Arial",sans-serif"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial",sans-serif"> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial",sans-serif">----- Original message -----<br>
From: "Stephen R Buchanan" <</span><a href="mailto:stephen.buchanan@us.ibm.com"><span style="font-size:12.0pt;font-family:"Arial",sans-serif">stephen.buchanan@us.ibm.com</span></a><span style="font-size:12.0pt;font-family:"Arial",sans-serif">><br>
Sent by: </span><a href="mailto:gpfsug-discuss-bounces@spectrumscale.org"><span style="font-size:12.0pt;font-family:"Arial",sans-serif">gpfsug-discuss-bounces@spectrumscale.org</span></a><span style="font-size:12.0pt;font-family:"Arial",sans-serif"><br>
To: </span><a href="mailto:gpfsug-discuss@spectrumscale.org"><span style="font-size:12.0pt;font-family:"Arial",sans-serif">gpfsug-discuss@spectrumscale.org</span></a><span style="font-size:12.0pt;font-family:"Arial",sans-serif"><br>
Cc:<br>
Subject: [gpfsug-discuss] Systemd configuration to wait for mount of SS filesystem<br>
Date: Thu, Mar 14, 2019 3:58 PM<br>
<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif">I searched the list archives with no obvious results.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif"> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif">I have an application that runs completely from a Spectrum Scale filesystem that I would like to start automatically on boot, obviously after the SS filesystem mounts, on multiple
nodes. There are groups of nodes for dev, test, and production, (separate clusters) and the target filesystems are different between them (and are named differently, so the paths are different), but all nodes have an identical soft link from root (/) that
points to the environment-specific path. (see below for details)<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif"> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif">My first effort before I did any research was to try to simply use a directive of After=gpfs.service which anyone who has tried it will know that the gpfs.service returns as "started"
far in advance (and independently of) when filesystems are actually mounted.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif"> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif">What I want is to be able to deploy a systemd service-unit and path-unit pair of files (that are as close to identical as possible across the environments) that wait for /appbin/builds/
to be available (/[dev|tst|prd]01/ to be mounted) and then starts the application. The problem is that systemd.path units, specifically the 'PathExists=' directive, don't follow symbolic links, so I would need to customize the path unit file for each environment
with the full (real) path. There are other differences between the environments that I believe I can handle by specifying an EnvironmentFile directive -- but that would come from the SS filesystem so as to be a single reference point, so it can't help with
the path unit.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif"> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif">Any suggestions are welcome and appreciated.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif"> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif">dev:(path names have been slightly generalized, but the structure is identical)<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif">SS filesystem: /dev01<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif">full path: /dev01/app-bin/user-tree/builds/<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif">soft link: /appbin/ -> /dev01/app-bin/user-tree/<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif"> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif">test:<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif">SS filesystem: /tst01<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif">full path: /tst01/app-bin/user-tree/builds/<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif">soft link: /appbin/ -> /tst01/app-bin/user-tree/<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif"> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif">prod:<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif">SS filesystem: /prd01<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif">full path: /prd01/app-bin/user-tree/builds/<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif">soft link: /appbin/ -> /prd01/app-bin/user-tree/<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif"> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Arial",sans-serif"> <o:p></o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:9.0pt;font-family:"Helvetica Neue"">Stephen R. Wall Buchanan</span></b><span style="font-size:9.0pt;font-family:"Helvetica Neue""><br>
Sr. IT Specialist</span><span style="font-size:10.5pt;font-family:"Arial",sans-serif"><br>
</span><span style="font-size:9.0pt;font-family:"Arial",sans-serif">IBM Data & AI North America Government Expert Labs</span><span style="font-size:10.5pt;font-family:"Arial",sans-serif"><br>
</span><span style="font-size:9.0pt;font-family:"Helvetica Neue"">+1 (571) 299-4601<br>
</span><a href="mailto:stephen.buchanan@us.ibm.com"><span style="font-size:9.0pt;font-family:"Helvetica Neue"">stephen.buchanan@us.ibm.com</span></a><span style="font-size:10.5pt;font-family:"Arial",sans-serif"><o:p></o:p></span></p>
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