aix

Fixing X11 Forwarding Over SSH and with Sudo

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X11 forwarding over SSH not working? Not setting $DISPLAY correctly in your shell? Having problems with X11 and sudo? Yeah, me too. Total pain in the duff. Here’s what I do to fix it. I’m thinking about Linux when I write stuff like this but a lot of this has worked on AIX and Solaris, too. Make sure your SSH client supports X11 Forwarding and that it’s turned on. I use SecureCRT but I know it works in PuTTY as well. Once you turn it on in your client & save the settings you will need to reconnect, the forwarding is established with the connection. Ensure xauth and xterm are installed. You need xauth for this to work, and xterm …

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When Should I Upgrade to VMware vSphere 6?

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I’ve been asked a few times about when I’m planning to upgrade to VMware vSphere 6. Truth is, I don’t know. A Magic 8 Ball would say “reply hazy, try again.” Some people say that you should wait until the first major update, like the first update pack or first service pack. I’ve always thought that approach is crap. Software is a rolling collection of bugs. Some are old, some are new, and while vendors try to make the number of bugs go down the truth is that isn’t the case all the time. Especially with large releases, like service packs. The real bug fixing gains are, to borrow a baseball term, in the “small ball” between the big plays. …

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AIX 6.1 & 7.1 Daylight Savings Time Issue

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If you’re running IBM AIX 6.1 or 7.1 at various SP & TL levels you might want to pay attention to a potentially big timezone/DST issue that my AIX coworkers have been struggling with this week. In short, the Daylight Savings Time code doesn’t work right and causes the time to change at incorrect times. In many cases a reboot is required to make things work correctly. The support document from IBM says: AIX systems or applications that use the POSIX time zone format may not change time properly at Daylight Savings Time start or end dates. Applications that use the AIX date command, or time functions such as localtime() and ctime(), on these systems may be affected. … You …

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GNU Screen For Fun and Profit

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My friends and fellow virtualization professionals Tim Oudin & Joep Piscaer & Paul Gear and some commenters reminded me that the perfect complement to SSH session instability is the GNU utility ‘screen’. Indeed, I’ve been using it for years, and I recommend it to everybody doing any significant work in an SSH session. As the FSF puts it, “screen is a full-screen window manager that multiplexes a physical terminal between several processes, typically interactive shells.” In short, it virtualizes your interactive shell session so you can disconnect from it and reconnect to it as needed. On Linux hosts it usually comes as a package, else you can download it from gnu.org and compile it. I’ve built it on DEC UNIX and AIX in …

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Who Cares About Time Zones Anyway?

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If you think you have a thankless job you should think about Arthur David Olson and Paul Eggert. Heck, it’s not even a paying job for them. They’re volunteers. Perhaps even masochists. What do they do? They maintain the time zone database (“zoneinfo”) for all of the computing world. And while residents of a particular country have to put up with just the general stupidity of their own politicians, these guys have to put up with all the stupidity of all politicians, across the Earth. Every time a politician in Russia, or Cameroon, or Indiana thinks it’d be a good idea to screw with the clocks these guys update and redistribute their database[0]. Vendors pick up the update and send …

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Why I Don't Use Third-Party Binary Packages

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There are a number of third-party package repositories out there for Linux distributions. For example, Fedora runs the Extra Packages for Enterprise Linux (EPEL) repository, which contains builds of open source software that isn’t supplied with Fedora or Red Hat Enterprise Linux. Similarly, a lot of projects have their own repositories that supply builds of software for OpenSUSE, Debian, Ubuntu, etc. Maybe it’s just because I’m old-school, and maybe it’s because I enjoy compiling things, but I really don’t like the idea of using binaries found on the Internet. I never have. As an aside, I really tried hard to make the rest of this post not be critical, or seem like criticism, but instead just be a reflection of …

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