{"id":9363,"date":"2019-01-15T23:19:00","date_gmt":"2019-01-15T22:19:00","guid":{"rendered":"http:\/\/arumel.com\/?p=9363"},"modified":"2019-01-15T23:25:54","modified_gmt":"2019-01-15T22:25:54","slug":"script-to-configure-hugepages-in-linux","status":"publish","type":"post","link":"https:\/\/arumel.com\/en\/script-to-configure-hugepages-in-linux\/","title":{"rendered":"Script to configure HugePages in Linux"},"content":{"rendered":"

Script to configure HugePages in Linux<\/h1>\n

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Sometimes you have just finished the installation of the operating system (OEL in our case) and you want to configure the hugepages for the SGA of Oracle.<\/p>\n

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Here you can see one script to configure the 80% from the total memory in the machine (you can change this percentage if you want).<\/p>\n

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* Attention! –> You need to be sure that nothing more is running in your machine because if you have one Oracle Database you need to run this other script “Oracle Linux: Shell Script to Calculate<\/em>
\nValues Recommended Linux HugePages \/ HugeTLB Configuration (Doc ID 401749.1)<\/em>”<\/p>\n

[root@nodo01 ~]# chmod 700 \/tmp\/config_hugepages80.sh\r\n\r\n[root@nodo01 ~]# cat \/tmp\/config_hugepages80.sh\r\n#!\/bin\/bash\r\n\r\nround() {\r\n# Funci\u00f3n para sacar la media de las cpus (de la funci\u00f3n mira_cpus) ya que en algunas bash no funciona el t\u00edpico:\r\n# echo \"(`lscpu |grep ^\"CPU(s):\" | awk -F: {'print $2'} | tr -d '[:blank:]'`)\/2\" | bc\r\necho $(printf %.$2f $(echo \"scale=$2;(((10^$2)*$1)+0.5)\/(10^$2)\" | bc))\r\n}\r\n\r\nmemlibre=`awk '\/Hugepagesize:\/{p=$2}\/ 0 \/{next}\/ kB$\/{v[sprintf(\"%9d GB %-s\",int($2\/1024\/1024),$0)]=$0;next}{h[$0]=$2}END{for(k in v) print k;for (k in h) print sprintf(\"%9d GB %-s\",p*h[k]\/1024\/1024,k)}' \/proc\/meminfo|sort -nr|grep --color=auto -E \"^|.(Huge._[TF]|Mem).*:|\" |grep MemFree | awk '{ print $4 }'`\r\n\r\npagesize=`awk '\/Hugepagesize:\/{p=$2}\/ 0 \/{next}\/ kB$\/{v[sprintf(\"%9d GB %-s\",int($2\/1024\/1024),$0)]=$0;next}{h[$0]=$2}END{for(k in v) print k;for (k in h) print sprintf(\"%9d GB %-s\",p*h[k]\/1024\/1024,k)}' \/proc\/meminfo|sort -nr|grep --color=auto -E \"^|.(Huge._[TF]|Mem).*:|\" |grep Hugepagesize | awk '{ print $4 }'`\r\n\r\nhps=`echo $(round ${memlibre}\/${pagesize} 0)`\r\npags=`echo $(round ${hps}*80\/100 0)`\r\n\r\necho \"${pags}\" > \/proc\/sys\/vm\/nr_hugepages\r\necho \"vm.nr_hugepages = ${pags}\" >> \/etc\/sysctl.conf\r\n\r\nsysctl -p >>\/dev\/null\r\n\r\nawk '\/Hugepagesize:\/{p=$2}\/ 0 \/{next}\/ kB$\/{v[sprintf(\"%9d GB %-s\",int($2\/1024\/1024),$0)]=$0;next}{h[$0]=$2}END{for(k in v) print k;for (k in h) print sprintf(\"%9d GB %-s\",p*h[k]\/1024\/1024,k)}' \/proc\/meminfo|sort -nr|grep --color=auto -E \"^|.(Huge._[TF]|Mem).*:|\"<\/pre>\n
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If you want to modify the percentage (80%) you can do it in the line “pags=” and changing the 80 number for another value.<\/p>\n
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Execute it:<\/p>\n
[root@nodo01 ~]# \/tmp\/config_hugepages80.sh<\/strong>
\n32767 GB VmallocTotal: 34359738367 kB
\n39 GB MemTotal: 41186732 kB<\/strong>
\n34 GB DirectMap1G: 35651584 kB
\n28 GB HugePages_Total: 14416<\/strong>
\n28 GB HugePages_Free: 14416<\/strong>
\n10 GB MemAvailable: 10550832 kB<\/strong>
\n9 GB CommitLimit: 10025680 kB
\n7 GB MemFree: 7384284 kB<\/strong>
\n6 GB DirectMap2M: 7243776 kB
\n3 GB SwapTotal: 4194300 kB
\n3 GB SwapFree: 4194300 kB
\n3 GB Cached: 3452204 kB
\n1 GB Inactive(file): 1995756 kB
\n1 GB Inactive: 2011316 kB
\n1 GB Active(file): 1446100 kB
\n1 GB Active: 1462444 kB
\n0 GB SUnreclaim: 82040 kB
\n0 GB SReclaimable: 122556 kB
\n0 GB Slab: 204596 kB
\n0 GB Shmem: 16960 kB
\n0 GB PageTables: 2228 kB
\n0 GB Mapped: 33532 kB
\n0 GB KernelStack: 3696 kB
\n0 GB Inactive(anon): 15560 kB
\n0 GB HugePages_Surp: 0
\n0 GB HugePages_Rsvd: 0
\n0 GB Hugepagesize: 2048 kB
\n0 GB Dirty: 4 kB
\n0 GB DirectMap4k: 96256 kB
\n0 GB Committed_AS: 126564 kB
\n0 GB Buffers: 6608 kB
\n0 GB AnonPages: 15044 kB
\n0 GB Active(anon): 16344 kB<\/p>\n
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Don’t forget to reboot the system and check the modified values!<\/em><\/strong><\/p>\n
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