Administration tips and tricks - Revision history

Pascal-ernster-7ce9@ruhr-uni-bochum.de: Removed otherwise empty category "HPC-Admin-TipsTricks"

2020-05-25T13:43:05Z

Removed otherwise empty category "HPC-Admin-TipsTricks"

2020-01-20T01:04:23Z

Mutual dependencies of services

2020-01-20T01:02:15Z

Mutual dependencies of services

2020-01-20T00:59:27Z

Mutual dependencies of services

2019-11-03T13:20:38Z

2019-11-03T13:02:33Z

2019-10-01T15:32:02Z

Mutual dependencies of services

2019-10-01T15:28:24Z

Mutual dependencies of services

2019-10-01T15:21:54Z

Mutual dependencies of services

2019-10-01T15:21:09Z

Mutual dependencies of services

← Older revision		Revision as of 13:43, 25 May 2020
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	[[Category:HPC-Admin]]		[[Category:HPC-Admin]]
−	~~[[Category:HPC-Admin-TipsTricks]]~~

	== Mutual dependencies of services ==		== Mutual dependencies of services ==

@@ Line 21: / Line 21: @@
    mmaddcallback NameOfCB --command '''/bin/systemctl''' --parms "'''start slurmd'''" --event ''startup'' -N all,your,compute,node,classes,as,defined,in,GPFS
-The event ''startup'' is in fact GPFS's "local full readiness" state. The callback will thus be called on each node ''only after'' it has completed all GPFS joining and mounting stuff, then in effect running
+The event ''startup'' is in fact GPFS's "local full readiness" state. The callback will thus be called on each node ''only after'' it has completed all GPFS arbitrating, joining and mounting stuff, then in effect running
    '''/bin/systemctl start slurmd'''
 which is what you want.

@@ Line 15: / Line 15: @@
 ;Suggestion
-Try to "turn the tables" and check whether your [[HPC-Dictionary#Shared filesystems|shared filesystem]] supports any kind of "Now, I am really ready and operational" callback or signal.
+Try to "turn the tables" and check whether your [[HPC-Dictionary#Shared filesystems|shared filesystem]] supports any kind of callback or signalling to tell "Now, I am really ready and operational".
 Then, have your [[HPC-Dictionary#Shared filesystems|shared filesystem]] start up your local scheduler daemon--when all is ready.

@@ Line 18: / Line 18: @@
 Then, have your [[HPC-Dictionary#Shared filesystems|shared filesystem]] start up your local scheduler daemon--when all is ready.
-In the case of GPS, you can define "user callbacks" which are triggered ''locally on each node'' at certain events. Creating such a callback (using <code>systemd</code> and <code>slurmd</code> as an example):
+In the case of SpectrumScale (GPFS), you can define "user callbacks" which are triggered ''locally on each node'' at certain events. Creating such a callback (using <code>systemd</code> and <code>slurmd</code> as an example):
    mmaddcallback NameOfCB --command '''/bin/systemctl''' --parms "'''start slurmd'''" --event ''startup'' -N all,your,compute,node,classes,as,defined,in,GPFS

← Older revision		Revision as of 13:20, 3 November 2019
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	[[Category:HPC-Admin]]		[[Category:HPC-Admin]]
		+	[[Category:HPC-Admin-TipsTricks]]

	== Mutual dependencies of services ==		== Mutual dependencies of services ==

@@ Line 11: / Line 11: @@
 Or you could write fine-grained ''systemd'' dependencies (with <code>PathExists=</code> or <code>DirectoryNotEmpty=</code>.
-All these will fail inevitably, if the [[HPC-Dictionary#Shared filesystems|shared filesystem]] takes longer than expected to get operational.
+All these will fail inevitably, if the [[HPC-Dictionary#Shared filesystems|shared filesystem]] takes longer than expected to become operational.
 ;Suggestion

@@ Line 22: / Line 22: @@
 The event ''startup'' is in fact GPFS's "local full readiness" state. The callback will thus be called on each node ''only after'' it has completed all GPFS joining and mounting stuff, then in effect running
    '''/bin/systemctl start slurmd'''
-On your nodes, simply disable the systemd unit of your local scheduler's daemon:
+To exempt the systemd unit of your local scheduler daemon from being auto-started during boot, simply disable it (which in effect only removes a symbolic link):
    systemctl disable slurmd
-and watch the next reboot for the orderly coming up of GPFS, followed by <code>slurmd</code>.
+and watch the next reboot for the orderly coming up of GPFS, duly followed by <code>slurmd</code>.