Asides

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Ubuntu 18.04 (Bionic Beaver) – Some notable changes for sysadmin and Java dev

If you administer a Ubuntu server or if you are a power user, you might have a look at these particular changes in Ubuntu before and after upgrading. They can impact your installation and the way you use it.

  • NTP is no longer supported (part of Universe), you should use now Chrony. My opinion is that Chrony is not a bad choice either, it’s perhaps smoother in handling leap seconds (via smearing) but obviously less accurate than NTP in the case.
  • The local DNS resolver is no longer dnsmasq but systemd-resolvd. For most user this should be transparent. Note that if systemd-resolvd does not receive a DNS configuration, it will fallback to using Google Public DNS.
  • Network will be now managed by systemd-networkd (or still by NetworkManager on the desktop) for new installation. If you upgrade, you will still have the old `/etc/network/interfaces` file (and al) and the ifup and ifdown scripts. But this is no longer installed on new installation. Instead you have systemd-networkd and netplan. For people upgrading there is (not yet) clear path to switch to the new tools if wished.

Ubuntu 18.04 offers many more changes and I’m looking forward to upgrade my desktop and server. There are other changes not mentioned above which should be evaluated before upgrading. But I consider the above ones as core element which everybody needs whatever the purpose of the server is.

For developers, I would take care with Java and the OpenJDK. Ubuntu 16.04 LTS came with OpenJDK 8 which is the current LTS version of Java. The next LTS version of Java is 11 which is not yet published. Ubuntu 18.04 will come with OpenJDK 10 (a short-term support edition) by default and will switch the default to OpenJDK 11 when it will be released (hopefully only for new installation). Ubuntu will still provide OpenJDK 8 in universe for 18.04 with security support provided until EOL of Ubuntu 16.04 LTS (so until April 2021) to offer developer a transition time (while waiting for Java 11 to be published, matured and application migrated/validated on this new platform).

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24 – Happy Birthday Linux

I was too young to have witness this and I had never heard of the internet, e-mails or usenet at that time. But it’s amasing to look once back and see how much technology and connectivity is so much more accessible, and that this simple hobby which was Linux at that time is now everywhere, even in space!

Hello everybody out there using minix –
I’m doing a (free) operating system (just a hobby, won’t be big and professional like gnu) for 386(486) AT clones. This has been brewing since april, and is starting to get ready. I’d like any feedback on things people like/dislike in minix, as my OS resembles it somewhat (same physical layout of the file-system (due to practical reasons) among other things).
(…)
PS. Yes – it’s free of any minix code, and it has a multi-threaded fs. It is NOT portable (uses 386 task switching etc), and it probably never will support anything other than AT-harddisks, as that’s all I have :-(.
—Linus Torvalds

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.Space I could not resist you

I don’t have much time to explore more my Raspberry Pi or other technical stuff lately, because I have lots of interesting (and also demanding) stuff to do in my non-cyber life (the real one)!

But I always have an eye on what’s happening there and when I saw availability of the .space domain, I hesitated a few months before I could not resist it any longer.

You can now visit my site using berthon.space! You will land for the moment on the same page. I have time now to think how I will personalise this domain.

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Closing comments

Comments are the feature least used on this blog. In addition, they could pose a security risk by allowing anonymous user entries (see WordPress 4.2 Stored XSS). I am therefore closing them and I am not sure I will reopen them in the future.

I plan to move this blog to a static blog engine (such as Octopress but I haven’t selected one yet). Such engine – as far as I know – do not support comments and I don’t want to rely on 3rd party products such as disqus for obvious privacy reasons which I’m not going to details now.

There are several ways to continue the discussion with me. Social “media” are one, and eventhough I’m not really active there, I’m monitoring them. I will think of other ways to provide discussions and update this post.

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Comments blocked on Magical World

Today I took the decision to block all comments on Magical World.

Spammers are currently flooding the blog with spam which are filling up our backend database (it is a small and cheap hosting service). Although all spam are captured by our spam filter, we end up with our hosting service provider blocking SQL insert and update statements. It basically freezes our website.

In the near future I will evaluate a better solution and restore comments. But for the time being, feedback can be provided to us via the contact us page.

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App security is really low

Web browsers have had since ages a small lock to tell their users when they were securely connected to a web server.

Apps, especially those for mobiles, do not expose this information. It is very difficult to know if they use proper encryption, or that they even check the validity of the encryption certificates (when using methods such as SSL or TLS). Without such encryption, user credentials (login and password) and the exchanged personal data can easily be snooped.

App makers should mandatorily use encryption for communication. And they should use certificates to make sure they connect to the expected server. And they should expose that to the user interface!

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Finally someone got it right regarding 64-bit performance increase:

It seems that the bulk of the A7’s performance gains do not come from any advantages inherent to a 64-bit architecture, but rather from the switch from the outdated ARMv7 instruction set to the newly-designed ARMv8. – iFixit iPhone 5s Teardown

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HI (Human Intelligence) in Computer Science

The number of errors you find in forums or user groups is sometimes amazing. Here in this thread, the first answer mix up file system journaling with indexing, the second rightly tries to correct the thread but adds more errors by stating that ZFS is a journaling FS, which it isn’t. It is a transactional copy-on-write file system.

And this other thread on Ubuntu Forums is even worse. First, people do not exactly answer the question, some just express opinion/beliefs without facts, finally some are trying to base their answers on facts but those are incorrect. Example: “NTFS does not have a journal, neither is it 64 bit like Ext4.” (it is pretty hard to have that many wrong facts in one sentence, bravo!) Thanks, some users are trying to sanitize this thread (e.g. Udayakiran or falconindy), sadly their answers are flooded in the mass of bad/wrong ones.

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ZFS on Linux

In my previous post, I was stating that ZFS on Linux was not mature enough. The native ZFS port to Linux, although active, is still in release candidate stage and requires significant work to install. As for the ZFS FUSE version, it is still a 0.7 version not updated for long but it is easy to install on Ubuntu as it is available in the Software Centre (the link only works if your system supports the ‘apt:‘ scheme like on Ubuntu).

I have tried and installed the later, and although I cannot give any conclusion from a stability/reliability point of view, I was able to perform successfully the same steps I had performed on FreeBSD using ZFS.