A few years ago, when I was still in charge of the Toronto Community Co-Location Project (a project that I’m pretty sure is defunct by now), I was approached by a fellow named Da Shi, who was just starting a company called 3z Canada. He provided some competitive rates for co-location, but we ultimately sublet space from Chris Kirby. Continue reading
64-bit Xen considered harmful
Recently at work, we tried to implement Xen on Intel Xeon, running a 64-bit dom0/domU. I have to say that this failed horribly, so I’m writing this post to warn others off it. My colleague Gabriel worked hard to migrate everything back to a 32-bit environment, so kudos to him.
The specific symptoms we experienced while running 64-bit Xen is that the domU’s would crash and reboot randomly under (or after) high load. One of our domU’s is a development server, which also runs a CruiseControl, a continuous integration system. This means that every minute, CruiseControl wakes up, does a cvs update to see if there are any changes, and then recompiles the project(s) if needed. Periodically we started to see error messages like
Bad pte = 32971e067, process = cvs, vm_flags = 100077, vaddr = b7f34000
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After a few of these, domU would reboot. It seems like others are having the same problem on 64-bit Xen. This user was running CentOS 5.1, which is basically what we’re running (we have the real deal Red Hat Enterprise LInux 5.1).
As I said, migrating the domU back to a 32-bit dom0 seemed to fix this, so let this be a fair warning to others thinking of running a 64-bit dom0.
computer equipment upgrade time
It’s that time of year again when I start to think about what computer upgrades I might want to do. I’ve had some annoying things happen with my desktop PC recently and have considered either replacing it entirely, or implementing some much-needed upgrades. Continue reading
VAX/VMS on Linux using SIMH
Some of you are aware that I’m into vintage computers. Sadly, my basement cannot hold all the computers I wish I could actually have – and some of them are forever going to be too big to fit in any man’s house (not to mention “make it past a man’s significant other“).
But why would one actually need a VAX when, these days, one can emulate one on a Linux PC using SIMH? Not only can one emulate a VAX (take your pick: MicroVAX or VAX 11/780) but also a PDP-11, Data General Nova, some ancient Honeywell mainframes I’ve never heard of, or a bunch of other old mainframes or minicomputers.
I have a special nostalgia for the VAX, since I accessed my first real e-mail account at the National Capital Free-Net via a VAX in my dad’s office. On the anniversary of my Dad’s retirement, I’ve decided I’m going to try to get a VAX running in emulation under SIMH – running OpenVMS, no less. Do I know anything about running OpenVMS? Nope, I do not – but I’m going to find out. Yes, I know it’s a nearly obsolete operating system, and DCL is not the most intuitive. But hopefully it should prove to be a little bit amusing at least – wish me luck!
(On a completely unrelated note: People are still writing in to comment on the blog post where I got yelled at by Drew of Toothpaste For Dinner for offering an RSS feed. Haha! I’ve moved onto reading xkcd these days … that fellow seems far less uptight, and his comics are more reliably funny. And yes, xkcd has an RSS feed, if you had to ask.)
stupid Internet memes
April Fool’s Day is upon us again, and along with this are some truly stupid April Fool’s jokes. Chief among them was YouTube’s replacement of its featured videos with ones that actually link to Rick Astley’s Never Gonna Give You Up, a common Internet meme known as "rickrolling". Now characterize me as an old codger, but I have to say that rickrolling is one of the stupidest Internet memes I have ever come across. I really don’t see what’s so funny about this. Maybe I’m missing something? It’s been done many times over, even in xkcd cartoons, but really folks, it’s not funny, and it should just be put to rest.
I’ll tell you what I found really funny: the folks over at Atlassian who announced the JIRA Solver. Some of you may recall that Cenqua (now a wholly owned subsidiary of Atlassian) presented both the PairOn extreme-programming chair and the Commentator automated code-commenter (commentator?) on 1 April 2005, both of which were a riot. Now that’s creative… perpetuating a lame Internet meme is not.
HP’s website is funny
I always laugh whenever I visit Hewlett-Packard‘s website. I have no idea what kind of crazy spaghetti computer systems they have running the site, but URLs of the format h20000.www2.hp.com make me imagine that the site is being fronted with Apache running on OpenVMS/VAX, with the back-end running Nonstop on a Tandem minicomputer. (All products that HP owns.)
I received the following error message today:
Message from the ISAPI plugin:
No backend server available for connection: timed out after 10 seconds or idempotent set to OFF.
Build date/time: Jun 15 2006Change Number: 779505
I dearly hope idempotent is not set to OFF. Unless HP/UX really is that bad and you need to keep trying so that at some point you’ll get the answer you were looking for. (“1+1=3 … nope. 1+1=4 … nope. 1+1=2 … ah-ha!”)
Incidentally, i was trying to determine the oldest server that we still have in operation. We still have a few PA-RISC-based HP 9000 A-class systems running HP/UX; they’ve probably been past their prime now for about 7 years. I’ll let you know if I find anything older!
CBC to distribute “Canada’s Next Great Prime Minister” via BitTorrent
If you follow Slashdot, Digg, etc. you might already have heard of this, but CBC is going to distribute the final episode of Canada’s Next Great Prime Minister via BitTorrent immediately following the prime time broadcast of the show this evening. That’s right, a complete, DRM-free XVID AVI file, along with an H.264 version you can download to your iPod.
As a favour to them, I’ll be helping a couple of the folks from TV A&E seed the torrent file this evening. Hopefully the bandwidth demand won’t be too onerous.
For more info, check out the CNGPM blog entry on this topic.
fighting spam in GroupWise using IMAP
I have a serious problem with spam at work; I get perhaps 100 spams a day, 200 if it’s a bad day. Our IT department has repeatedly tried to implement anti-spam solutions in the GroupWise e-mail system, but to no avail — the promised reductions in spam haven’t materialized.
I decided to install ISBG, a/k/a IMAP Spam Begone. ISBG will log into an IMAP server, examine your Inbox, and run each of the messages against a local installation of SpamAssassin. You can then instruct ISBG to delete any spam message it finds.
I’ve installed ISBG and now invoke it from cron(8) every five minutes. So far, it’s living up to expectations! I highly recommend it for anyone with a sub-par email system that cannot properly handle spam filtering.
One quirk I’ve found with GroupWise is that I have no idea how to access subfolder names over IMAP. For example, if I want ISBG to move all my spams to a folder called “Spam” under my Cabinet, the folder doesn’t seem to have the name Cabinet.Spam. I haven’t yet figured out how to refer to that folder in the IMAP namespace. If you are a GroupWise under-the-hood hacker and know the answer, please let me know!
VIA Rail WiFi suckage
VIA Rail offers WiFi service aboard its trains. I’m on my way to Montreal for a business trip, so I thought I’d try it out. My conclusion: stay away!
It seems that VIA is partnered with a company called Parsons to provide the WiFi aboard the train. Judging by the latency, I can only assume that it is a satellite link. Check out what kind of latency you get for $8.95 per 24 hours of access:
C:>tracert aphrodite.aquezada.com Tracing route to aphrodite.aquezada.com [216.235.8.211] over a maximum of 30 hops: 1 1 ms 1 ms 2 ms VIA_3454 [192.168.134.1] 2 * * 3071 ms 10.0.15.1 3 4033 ms 3878 ms 3684 ms link1.parsons.com [206.219.255.131] 4 987 ms * 1154 ms 66.147.156.114 5 758 ms 1586 ms 798 ms ge-5-0.a0.dlls.broadwing.net [216.140.4.173] 6 899 ms 1457 ms 739 ms 216.140.4.158 7 697 ms 1180 ms 339 ms 216.140.4.170 8 633 ms 640 ms 859 ms te-8-3-73.car4.Dallas1.Level3.net [4.68.63.9] 9 2958 ms 2638 ms 1620 ms ae-13-69.car3.Dallas1.Level3.net [4.68.19.5] 10 1308 ms 1136 ms 1258 ms 4.68.63.162 11 2126 ms 2132 ms 2962 ms 5.icore1.CT8-Chicago.teleglobe.net [206.82.141.2 9] 12 * * * Request timed out. 13 944 ms 1572 ms 4343 ms if-15-0-0-15.mcore3.TTT-Scarborough.teleglobe.ne t [216.6.98.49] 14 887 ms 937 ms 1901 ms if-15-0.core1.TNK-Toronto.teleglobe.net [216.6.9 8.54] 15 1235 ms 477 ms 320 ms ix-1-151.core1.TNK-Toronto.teleglobe.net [216.6. 112.22] 16 1120 ms 1936 ms 2679 ms 204.16.202.173 17 * 3228 ms 1316 ms 216.235.0.236 18 1519 ms 1882 ms 3716 ms h216-235-8-211.host.egate.net [216.235.8.211] Trace complete.
Unless you’re just doing SSH — save your money!
Internet access RFQ from ten years ago!
I’m cleaning out my $HOME/doc directory and I found this gem from ten years ago, when I was still a student searching for a new ISP. How things have changed – “what 56k modem standard are you favouring?”
Dear Sir or Madam,
I am currently in the process of searching for a new Internet service provider in the Toronto area. I thought it might be best if I simply listed my access and web page requirements, along with technical questions I wish to have answered, and you will follow up with a price range. I can be reached by e-mail at jdunn@[deleted]
Access Requirements: max. 30 hours per month, analog 28.8 kbps modem
Web Site Requirements:
- 5 megs server space
- CGI directory (very important)
- access and error logs available
- unrestricted transfer rate from outside clients
Technical and administrative questions:
- Do you support, or are you planning to upgrade to, 56 kbps modem technology, and if so, which standard are you favouring/planning on favouring?
- What is your users-to-modem ratio?
- How long have you been in business?
- How many subscribers do you have?
- Whose backbone are you hooked into? (e.g. sprintlink, CANet, ONet, etc.)
- What are your technical support hours?
- How many tech support staff do you have?
- What kind of servers do you run on? Do different servers serve up mail, ftp, http, or does one machine handle it all?
- Are there any discounts for students?
If you could answer my questions and give me a price quote on the above requested services, with a breakdown if certain things are extra (e.g. unlimited transfer rate), I would really appreciate it.