Lightning sucks. A thunderblot struck our house and toasted my dsl splitter and my router. Did you ever want to know how a splitter that has been hit by a thunderblot looks? Here are the pictures.
After discovering mini-buildd, a tiny Debian buildd, I’ve tried to set it up inside some vservers. mini-buildd uses LVM-Snapshots to avoid duplicate work when creating build chroots. I will setup a base debian chroot once and create a snapshot each time a build chroot is needed. This, however, is where the fun begins. The problem is that Linux-Vserver prevents its guests from performing most of the syscalls and ioctls needed by lvm2.
I didn’t manage to get the setup fully working so far but I wanted to share my experience in case anyone tries the same!
The basic setup of mini-buildd is quiet easy. I’ve decided for a setup with three versers, one for the repository, one buildd for amd64 and ond buildd for i386.
Recently I’ve read a really interesting book. A book every perl developer should read. At least have a look at Appendix B which lists all guidelines in a brief summary.
Dear Deutsche Telekom,
I’ve just got to love your great CPE products. The Speedport W722V ist a great product, a impressive piece of german engineering! It provides lots and lots of usefull features. For example you can us it as a doorstop, paperweight or to prettify your home.
But the point is: It is absolutely useless as a Internet-Router for me! It doesn’t allow incoming ICMP (Ping), it got no internal S0 (ISDN) Bus and it doesn’t allow VPN-Passthrough (GRE, Protocol 21). I even suspect it to have a severely broken QoS, but I can’t proof that right now. And this is only after a few days of playing around with this device. Not to think of what I’d find if I gave it some more time.
Die Konfiguration unserer Speedports ist auf Einfachheit getrimmt. Der Reichtum an einstellbaren Funktionen und Konfigurationsoptionen ist nicht das Ziel der Entwicklung, eher schon eine Reduktion auf das Wesentliche.
[Telekom Team @ T-Online Foren]
The quote says that they aim for simplicity and not for features, and they’re good at it. Very good. This device is so simplistic that it is basically useless for all but the most basic users.
I’ll look for a better CPE and try to return this device as soon as possible. Maybe they find somebody who can make better use of it than me.
Update: It looks like the Speedport is killing long running connections after a while (a few hours at most). I’ve heard about that one … that’s very disappointing when working over SSH.
President Hugo Chavez announced the incident via his account on the social networking site Twitter.
ROFL, literaly.
This is was it looks like when most of the german nameservers are down. This image shows the traffic of popular .de site. The drop isn’t remotely as sharp as I thought it would be.
Wanna get rid of these annoying “Wide character in print” warning perl gives you sometimes when dealing with unicode/UTF-8?
Use
binmode(STDOUT, ":utf8");
on STDOUT or the appropriate filehandle, and perl will treat it as UTF-8 capable.
You could also use the “-CSDA” option to tell perl that.
Before:
#!/usr/bin/perl -w use charnames ':full'; print "\N{GREEK CAPITAL LETTER DELTA}\n";
Gives:
./wide_char.pl Wide character in print at ./wide_char.pl line 9. Δ
After:
#!/usr/bin/perl -w use charnames ':full'; binmode(STDOUT, ":utf8"); print "\N{GREEK CAPITAL LETTER DELTA}\n";
Ok, for most experienced perl programmers this is not new, but let me repeat it:
Threads in Perl are broken. Really, really, severe broken. Do not use threads with Perl.
Thread async is probably ok for smaller computations but for anything else use fork().
Not only are IPC-Signals really dangerous with threads and DBI can’t work with threads but also the memory usage is magnitudes higher with threads than with fork(). At the moment I’m hacking a perl app that uses a lot ressouces but I was impressed how fast I could kill my system with fair amout of concurrent threads. From Java I was used to threads being very lightweight, but with Perl this is the other way round. My app has its core part modularized and I’ve wrote it once using threads and once using fork(). The threads-version uses about 300MB RSS while the fork()ing version uses no more the 30MB RSS for the same workload. Quiet a difference.
Ja ist denn schon 1. April?
Es geschehen noch Zeichen und Wunder:
Using KVM/virt-manager in Debian sid is interesing. You’ll get nice and fresh errors from time to time. KVM is constantly improving but you have to deal with unexpected changes from time to time which tend to break existing VMs.
With the latest version I’ve got this error:
Error starting domain: internal error unable to reserve PCI address 0:0:3
The long text:
Traceback (most recent call last):
File “/usr/share/virt-manager/virtManager/engine.py”, line 589, in run_domain
vm.startup()
File “/usr/share/virt-manager/virtManager/domain.py”, line 1208, in startup
self._backend.create()
File “/usr/lib/python2.5/site-packages/libvirt.py”, line 317, in create
if ret == -1: raise libvirtError (‘virDomainCreate() failed’, dom=self)
libvirtError: internal error unable to reserve PCI address 0:0:3
The solution was to edit the /etc/libvirt/qemu/<domain>.xml and change the conflicting PCI id. The line looked like this before:
<address type=’pci’ domain=’0×0000′ bus=’0×00′ slot=’0×03′ function=’0×0′/>
and like that after the change:
<address type=’pci’ domain=’0×0000′ bus=’0×00′ slot=’0×02′ function=’0×0′/>
Don’t forget to reload libvirt after this change.
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