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Showing posts from December, 2016

Ubuntu Archive and CD/USB images complete migration to 4096 RSA signing keys

Enigma machine photo by Alessandro Nassiri [ CC BY-SA 4.0 ], via Wikimedia Commons Ubuntu Archive and CD/USB image use OpenPGP cryptography for verification and integrity protection. In 2012, a new archive signing key was created and we have started to dual-sign everything with both old and new keys. In April 2017, Ubuntu 12.04 LTS (Precise Pangolin) will go end of life. Precise was the last release that was signed with just the old signing key. Thus when Zesty Zapus is released as Ubuntu 17.04, there will no longer be any supported Ubuntu release that require the 2004 signing keys for validation. The Zesty Zapus release is now signed with just the 2012 signing key, which is 4096 RSA based key. The old 2004 signing keys, where were 1024 DSA based, have been removed from the default keyring and are no longer trusted by default in Zesty and up. The old keys are available in the removed keys keyring in the ubuntu-keyring package, for example in case one wants to verify things

Swapfiles by default in Ubuntu

4MB RAM card By default, in Ubuntu, we usually create a swap partition. Back in the day of 4MB RAM cards this made total sense, as the ration of RAM to disk space, was still very low. Things have changed since. Server, desktop, embedded systems have migrated to newer generations of both RAM and persistent storage. On the high performance side of things we see machines with faster storage in the form of NVMe and SSD drives. Reserving space for swap on such storage, can be seen as expensive and wasteful. This is also true for recent enough laptops and desktops too. Mobile phones have substantial amounts of RAM these days, and at times, coupled with eMMC storage - it is flash storage of lower performance, which have limited number of write cycles, hence should not be overused for volatile swap data. And there are also unicorns in a form of high performance computing of high memory (shared memory) systems with little or no disk space. Today, carving a partition and reserving twice