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What do the various pieces of uname -a output mean? Following is an example output:

Linux mymachine 2.6.18-194.e15PAE #1 SMP Fri Apr 2 15:37:44 EDT 2010 i686 i686 i386 GNU/Linux

I gather that Linux is the O.S, 2.6.18-194.e15PAE is the kernel version. What do the rest of the pieces mean?

Appreciate your help.

T I
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1 Answers1

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In order, the fields are:

  • "Linux": The machine's kernel name (e.g, OS).
  • "mymachine": The machine's node name (e.g, hostname).
  • "2.6.18-194.e15PAE": The kernel version
  • "#1 SMP Fri Apr 2 15:37:44 EDT 2010": The kernel version and build time.
  • "i686 i686": The processor type and hardware platform.
  • "i386": The architecture of the processor. (This and the two above basically all mean the same thing on most systems. They typically only differ on certain embedded platforms.)
  • "GNU/Linux": The operating system name.

For comparison, the uname -a from my Mac reads:

  • "Darwin" (hardware name)
  • "mymachine"
  • "Darwin Kernel Version 11.0.0" (version)
  • "Sat Jun 18 12:56:35 PDT 2011; root:xnu-1699.22.73~1/RELEASE_X86_64" (build time)
  • "x86_64" (processor architecture)
  • (The operating system name is omitted by the OS X version of uname for some reason, as are a few other fields.)
  • So, if I wanted to make sure that a server was up to date with patches, all I would have to do is look at that output and make sure the build was within the date range my admin policy specifies (last three months), right? –  Aug 15 '18 at 14:04
  • @AgapwIesu No. The build time in the output of `uname` only reflects the version of the kernel, not any other software on the system. –  Aug 15 '18 at 16:57
  • Ok, let me clarify, I am only concerned with making sure that the **OS** is up to date with patches to within 3 months of "today". I don't need to care about other software at this point. For that, is that kernel build date/time enough?... am I giving away that I am a Windows guy?... should this be a separate question? –  Aug 16 '18 at 14:08
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    @AgapwIesu Again: no. Having an up-to-date kernel does not mean that all (or even any) other software on the machine has been updated. –  Aug 16 '18 at 18:05
  • To be more precise: `i686 i686` is `machine hardware name` and `processor type`. `i386` is `hardware platform`. – Jan Feb 17 '23 at 09:51
  • Does kernel version "#1" can be different than 1? – Lem Mar 16 '23 at 15:24