From 39eb17f3ecfe2a456d91c38caa419a5314e78d7e Mon Sep 17 00:00:00 2001 From: Seth Hoenig Date: Fri, 8 Dec 2023 10:45:37 -0600 Subject: [PATCH] docs: describe the need for dmidecode in docs (#19348) --- website/content/docs/concepts/cpu.mdx | 6 ++++++ website/content/docs/upgrade/upgrade-specific.mdx | 8 ++++++++ 2 files changed, 14 insertions(+) diff --git a/website/content/docs/concepts/cpu.mdx b/website/content/docs/concepts/cpu.mdx index 9b6361fc6..e747fccd3 100644 --- a/website/content/docs/concepts/cpu.mdx +++ b/website/content/docs/concepts/cpu.mdx @@ -320,6 +320,12 @@ resources { } ``` +## Virtual CPU Fingerprinting + +When running on a virtualized host such as Amazon EC2 Nomad makes use of the +`dmidecode` tool to detect CPU performance data. Some Linux distributions will +require installing the `dmidecode` package manually. + [cpuset]: https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v1/cpusets.html [cpushares]: https://www.redhat.com/sysadmin/cgroups-part-two [numa_wiki]: https://en.wikipedia.org/wiki/Non-uniform_memory_access diff --git a/website/content/docs/upgrade/upgrade-specific.mdx b/website/content/docs/upgrade/upgrade-specific.mdx index e8a33cb69..04f48edd7 100644 --- a/website/content/docs/upgrade/upgrade-specific.mdx +++ b/website/content/docs/upgrade/upgrade-specific.mdx @@ -88,6 +88,14 @@ upgrading to Nomad 1.7. Operators are encouraged to ensure planned capacity meets expectations before upgrading. The [cpu concepts][cpu] documentation contains guidance in understanding how Nomad detects CPU metrics. +#### CPU EC2 Detection Changes + +Prior to Nomad 1.7, Nomad clients embedded a large lookup table of CPU +performance data for every EC2 instance type. In 1.7 and later Nomad instead +gathers this data by executing the `dmidecode` command. The `dmidecode` package +must be installed manually on some Linux distributions before the Nomad agent +is started. + #### CPU Core Isolation Starting in Nomad 1.7, Nomad tasks that specify CPU resources using the `cores`