{"id":337,"date":"2015-06-03T09:40:25","date_gmt":"2015-06-03T09:40:25","guid":{"rendered":"http:\/\/blogs.uct.ac.za\/blog\/big-bytes\/2015\/06\/03\/where-are-all-the-hpc-servers-disappearing-to"},"modified":"2022-09-26T21:02:45","modified_gmt":"2022-09-26T19:02:45","slug":"where-are-all-the-hpc-servers-disappearing-to","status":"publish","type":"post","link":"https:\/\/ucthpc.uct.ac.za\/index.php\/2015\/06\/03\/where-are-all-the-hpc-servers-disappearing-to\/","title":{"rendered":"Where are all the HPC servers disappearing to?"},"content":{"rendered":"<div>Those users still making use of\u00a0<a href=\"https:\/\/blogs.uct.ac.za\/hpc.uct.ac.za\">hpc.uct.ac.za<\/a>\u00a0will have noticed that a few worker nodes have vanished. As mentioned previously we&#8217;re investigating a new scheduler,\u00a0<a href=\"https:\/\/computing.llnl.gov\/linux\/slurm\/\">SLURM, Simple Linux Utility for Resource Management<\/a>. SLURM is a very different animal to PBS. Gone are the groups and queues, in their place are accounts and partitions. Management and reservation of resources is extremely granular and can also be very complex. \u00a0Below is an example where two maths users have GrpCPU limits set to 24 and have each submitted two 4 core jobs. One of these jobs is pending, why?<\/div>\n<div><\/div>\n<div><img decoding=\"async\" src=\"https:\/\/ucthpc.uct.ac.za\/wp-content\/uploads\/2015\/07\/slurm.png\" alt=\"\" border=\"0\" \/><\/div>\n<div><\/div>\n<div>The answer is that an overriding core reservation (GrpCPU) of 12 has been set on their common partition (maths) which means that only three 4 core jobs will run. This allows finer control of group behaviour.<\/div>\n<div><\/div>\n<div><img decoding=\"async\" src=\"https:\/\/ucthpc.uct.ac.za\/wp-content\/uploads\/2015\/07\/slurm2.png\" alt=\"\" border=\"0\" \/><\/div>\n<div><\/div>\n<div>There are many more features that we want to add to this new cluster and each requires a significant amount of testing so we have no release date yet.<\/div>\n","protected":false},"excerpt":{"rendered":"<div>Those users still making use of&nbsp;<a href=\"https:\/\/blogs.uct.ac.za\/hpc.uct.ac.za\">hpc.uct.ac.za<\/a>&nbsp;will have noticed that a few worker nodes have vanished. As mentioned previously we&#8217;re investigating a new scheduler,&nbsp;<a href=\"https:\/\/computing.llnl.gov\/linux\/slurm\/\">SLURM, Simple Linux Utility for Resource Management<\/a>. SLURM is a very different animal to PBS. Gone are the groups and queues, in their place are accounts and partitions. Management and reservation of resources is extremely granular and can also be very complex. &nbsp;Below is an example where two maths users have GrpCPU limits set to 24 and have each submitted two 4 core jobs. One of these jobs is pending, why?<\/div>\n<div><img decoding=\"async\" src=\"http:\/\/blogs.uct.ac.za\/gallery\/1253\/slurm.png\" border=\"0\"><\/div>\n<div>&nbsp;<\/div>\n<div>The answer is that an overriding core reservation (GrpCPU) of 12 has been set on their common partition (maths) which means that only three 4 core jobs will run. This allows finer control of group behaviour.<\/div>\n<div>&nbsp;<\/div>\n<div><img decoding=\"async\" src=\"http:\/\/blogs.uct.ac.za\/gallery\/1253\/slurm2.png\" border=\"0\"><\/div>\n<div><\/div>\n<div>There are many more features that we want to add to this new cluster and each requires a significant amount of testing so we have no release date yet.<\/div>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[4,5],"tags":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v21.4 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Where are all the HPC servers disappearing to? - UCT HPC<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/ucthpc.uct.ac.za\/index.php\/2015\/06\/03\/where-are-all-the-hpc-servers-disappearing-to\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Where are all the HPC servers disappearing to? - UCT HPC\" \/>\n<meta property=\"og:description\" content=\"Those users still making use of&nbsp;hpc.uct.ac.za&nbsp;will have noticed that a few worker nodes have vanished. As mentioned previously we&#039;re investigating a new scheduler,&nbsp;SLURM, Simple Linux Utility for Resource Management. SLURM is a very different animal to PBS. Gone are the groups and queues, in their place are accounts and partitions. Management and reservation of resources is extremely granular and can also be very complex. &nbsp;Below is an example where two maths users have GrpCPU limits set to 24 and have each submitted two 4 core jobs. One of these jobs is pending, why?&nbsp;The answer is that an overriding core reservation (GrpCPU) of 12 has been set on their common partition (maths) which means that only three 4 core jobs will run. This allows finer control of group behaviour.&nbsp;There are many more features that we want to add to this new cluster and each requires a significant amount of testing so we have no release date yet.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/ucthpc.uct.ac.za\/index.php\/2015\/06\/03\/where-are-all-the-hpc-servers-disappearing-to\/\" \/>\n<meta property=\"og:site_name\" content=\"UCT HPC\" \/>\n<meta property=\"article:published_time\" content=\"2015-06-03T09:40:25+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2022-09-26T19:02:45+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/ucthpc.uct.ac.za\/wp-content\/uploads\/2015\/07\/slurm.png\" \/>\n<meta name=\"author\" content=\"Andrew Lewis\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Andrew Lewis\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minute\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/ucthpc.uct.ac.za\/index.php\/2015\/06\/03\/where-are-all-the-hpc-servers-disappearing-to\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/ucthpc.uct.ac.za\/index.php\/2015\/06\/03\/where-are-all-the-hpc-servers-disappearing-to\/\"},\"author\":{\"name\":\"Andrew Lewis\",\"@id\":\"https:\/\/ucthpc.uct.ac.za\/#\/schema\/person\/c183ad1c0a1063124a72d63963ae9c7e\"},\"headline\":\"Where are all the HPC servers disappearing to?\",\"datePublished\":\"2015-06-03T09:40:25+00:00\",\"dateModified\":\"2022-09-26T19:02:45+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/ucthpc.uct.ac.za\/index.php\/2015\/06\/03\/where-are-all-the-hpc-servers-disappearing-to\/\"},\"wordCount\":168,\"publisher\":{\"@id\":\"https:\/\/ucthpc.uct.ac.za\/#organization\"},\"articleSection\":[\"hpc\",\"SLURM\"],\"inLanguage\":\"en-ZA\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/ucthpc.uct.ac.za\/index.php\/2015\/06\/03\/where-are-all-the-hpc-servers-disappearing-to\/\",\"url\":\"https:\/\/ucthpc.uct.ac.za\/index.php\/2015\/06\/03\/where-are-all-the-hpc-servers-disappearing-to\/\",\"name\":\"Where are all the HPC servers disappearing to? 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