Posts Tagged ‘sysadmin’

When your Mac’s display out stops working

I landed in San Francisco at around 10pm, hit the hotel in Santa Clara by 11.30pm, crashed, and woke up to give my tutorial at 9am. By 8.45am, I couldn’t get my 12″ MacBook to display out via HDMI or VGA to the projector, so I ran back to the room to get my 15″ rMBP instead.

Later on, I ran the Apple Hardware Test. Or what it’s called now, Apple Diagnostics. Everything came back just fine, which seemed odd.

The best fix seemed to then be resetting the NVRAM. That didn’t improve things, so I had to reset the System Management Controller (SMC), and voila! everything seemed to work thereafter.

In the years of using Apple hardware, I have to think this is the first time I’ve had to do this. I guess the presentation pro-tip here is always carry a backup presentation device (I might going forward get the relevant dongles for the iPad to run a presentation too).

Starting with systemd

I currently maintain a host of machines in the RPM world from CentOS 5, CentOS 6, and now Fedora 20 (in preparation for CentOS 7). Being part of an upstream project that ships on many platforms, it is in my interest to make sure that all things “just work” on the myriad of platforms out there that we support.

In CentOS 6.5, changing a hostname is a process of editing /etc/sysconfig/network, making sure the /etc/hosts file is sensible and fixing it with the hostname command. Rackspace has a good support article on this.

This is the world before systemd. Now in Fedora 20, this muscle memory goes away in favour of using hostnamectl (docs from the excellent System Administrator’s Guide). Now all I have to do is: sudo hostnamectl set-hostname <newhostname>.

I see a whole host of feature requests with regards to MariaDB & systemd as well as a couple for MySQL. I’ll be spending some time on this in the near future.

(and in other news, shutdown doesn’t understand the -f switch – invalid option code – this was to skip fsck on reboot – still valid in CentOS 5, accepted input in CentOS 6, but unlikely for CentOS 7.)

Spacewalk, and what we can learn about naming

Red Hat releases Spacewalk. It is described as: “the upstream community project from which the Red Hat Network Satellite product is derived“. Congratulations to all whom have worked on it, especially my friends who tired endlessly over it in the past.

Red Hat, is sticking true to its promise, of open sourcing everything they make. Best of all, they recognise Fedora (they always did, since say, Fedora Core 2 or 3), CentOS (a direct “competitor”/rebuild of RHEL), and Scientific Linux (I know of a certain university’s sysadmin who will be blessing Spacewalk, as her life will now be a lot easier).

There have been a few blogs about it… Matt Asay asks about a community (Red Hat traditionally wasn’t good at this, but with Fedora, I believe they’ve learned, and I’m happy to say I think, I helped in the education process). No one however, focused on the technical aspects around Spacewalk/RHN.

Case in point: Oracle is at the heart of it. RHN was designed almost seven years ago, and I’ve heard amazing stories from Gafton, Greg, and Peter. How Gafton found hidden “secrets” inside Oracle to boost performance, and a whole bunch of interesting things, best to talk about over a beer (the irony? When I first met these folk, I couldn’t even legally drink a beer in the US…)

Read the Developer Documentation, note that they use Perl, Python and Java in the current code base (but only Perl and Java is the way forward). There’s a DB Schema available… and I wonder when someone will port this to MySQL?

The Spacewalk FAQ mentions the lack of resources in the past to add an open source database, but would want to do so soon. There’s even help on getting Oracle XE running. The glimmer that there is to be an open source database behind Spacewalk, is what tells me that the MySQL community, that benefit from such a tool (so you’re a DBA and a sysadmin at a fairly largeish installation), should port this to run on MySQL.

What else can we take away from Spacewalk? The excellent positioning. A community project from which the RHN product is derived. This is similar to what Fedora is positioned as: Another striking difference of Fedora is our goal to empower others to pursue their vision of what a free operating system should be like. Fedora now forms the basis for derivative distributions such as Red Hat Enterprise Linux , the One Laptop Per Child XO and Creative Commons’ Live Content DVDs.

Distinctive naming. Helps create a lack of confusion (at the price of an ubiquitous name? Sure, you just have two ubiquitous names now). MySQL Enterprise vs. MySQL Community. They’re both MySQL (don’t even get started on the odd/even numbering scheme…). I dream the day, when we have MySQL Enterprise and Sakila (formerly known as MySQL Community).