Difference between revisions of "Packages"

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You can also use the web interface at http://packages.ubuntu.com/
 
You can also use the web interface at http://packages.ubuntu.com/
  
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=== Remove old kernels ===
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Kernels take up a lot of disk space. And once you've got a new one, the old ones really don't serve a purpose. <code>autoremove</code> is supposed to remove old kernels (keeping the currently running kernel plus the prior one or two for backups).
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<source lang="bash">
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sudo apt-get autoremove
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</source>
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But sometimes old kernels are left lying around.  Maybe a lot of them. I'm not sure why, because normally you would only be left with 2 or 3 kernels if you run autoremove (perhaps this is because you have old virtualboxes?).
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The post-install script <code>/etc/kernel/postinst.d/apt-auto-removal</code> is responsible for keeping track of what to preserve. And it writes a manifest to <code>/etc/apt/apt.conf.d/01autoremove-kernels</code>.
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<source lang="bash">
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# run the post-install script
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sudo /etc/kernel/postinst.d/apt-auto-removal
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# see what's reserved
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cat /etc/apt/apt.conf.d/01autoremove-kernels
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</source>
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Let's use <code>dpkg</code> to see all the kernels that are currently installed.  Note: there are other related packages like headers (<code>linux-headers-*</code>), but those are dependencies of the kernel images, and will be removed when we remove the images so we don't need to even look at them.
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<source lang="bash">
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# the last pipe uses a simple extended grep to take the meta package 'linux-image-generic' out of our list
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dpkg -l linux-image* | awk '/^ii/ { print $2 }' | grep -e [0-9]
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# more complete perl-compatible regex to highlight the kernel release number
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dpkg -l linux-image* | awk '/^ii/ { print $2 }' | grep -P '[0-9]+\.[0-9]+\.[0-9\-]+[0-9]+'
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</source>
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Manually compose an <code>apt-get purge</code> invocation of the kernels you don't want (keep the running kernel and the prior as a fallback).
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<source lang="bash">
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sudo apt-get -y purge linux-image-3.13.0-44-generic linux-image-3.13.0-46-generic linux-image-3.13.0-48-generic linux-image-3.13.0-55-generic linux-image-3.13.0-71-generic linux-image-3.13.0-74-generic
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</source>
  
 
== RedHat and derivatives ==
 
== RedHat and derivatives ==
  
 
There is [[Yum]] package manager for RedHat and derivatives.
 
There is [[Yum]] package manager for RedHat and derivatives.
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== See Also ==
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[[Regular Expressions]]
  
 
[[Category:System Administration]]
 
[[Category:System Administration]]

Revision as of 01:20, 4 January 2017