Present Perfect

I never really got why the Mac is thought to be so userfriendly. This weekend we planned to backup and upgrade an older 2007 iMac running 10.4 Tiger to 10.5 Leopard.

I first wanted to make sure we could make a bootable copy of the hard drive. We got a WD MyBook Studio which is supposedly what you'd get for a Mac, with a fancy e-ink display for name and space left.

When attached to Firewire it first of all was not recognized at all. Over USB it worked, and recommended we do a firmware upgrade. After doing the firmware upgrade and rebooting, the drive wouldn't light up anymore. A heavy paperweight, essentially. Trickery with dmesg showed that something does get recognized on the USB port, but that's it. After an hour and a half of trying out various firmware uploading tools, we gave up and sent it back to the store, and settled for a standard no-additional-firmware USB drive.

Let Superduper run for a night backing up 120 GB of drive over 4 hours, and we were good to go (incidentally, I created two boot partitions, so after naming the first one 'Bootie', the second one named itself. A for the system drive, B for the first boot drive, and C for the second.)

Then comes the reboot. You're supposed to hold the Option key during boot. With Macs, this always gives me anxiety - do you start holding down a key before or after you turn it on ? Can you hold it down while you are rebooting ? When can you let go ? There are simply no clues. Between the sound, the grey screen, and the apple, you have no idea what is going on. At least, with the usual PC boot screens, you can check for common problems like 'is the keyboard even working'. I get Apple Anxiety all the time.

In this particular case, apparently I misremembered what the Option key was in the first place. I was holding down that four-lobed rotated clover key. But apparently Option is the Alt/railroad join key.

How is not labeling a key with the same name your software uses considered userfriendly by anyone ?

After holding down that railroad join key before rebooting until a boot menu pops up, we could choose the Bootie drive and boot from it. At least that bit was easy to use, and worked.

Make another backup just in case, then reboot with an official install CD of 10.5 from work.

This time you have to hold down the C key. I still don't understand why having to search the net for random information JUST so you can boot from a CD is so much better than a simple boot menu and a prompt to get into it.

And after a lot of whirring and booting into the installer, it simply pops up a message saying 'Mac OS X cannot be installed on the computer.' This software cannot be installed on this computer.

No further explanation. How hard could it be to tell me ?

Googling, it turns out that grey install discs are tied to a specific model. The disc came from a MacMini.

And again, after much Googling, it looks like the 30 euro retail version of Snow Leopard can be installed over Tiger on intel Macs, so maybe we should just wait until Monday to upgrade.

Now, if only we could actually get the CD out of the drive when rebooting, as the installer runs from CD it doesn't let you eject, and when you reboot I don't know the magic key combination to eject... and I just *know* I've had to do this before on a MacMini and all I remember is that it was some stupid combination of tricks...

I never really got why the Mac is thought to be so userfriendly. This weekend we planned to backup and upgrade an older 2007 iMac running 10.4 Tiger to 10.5...

I got my N900 back. The micro-USB port had broken off cleanly. Apparently that's a known thing. I brought it to a Nokia Support Centre and they fixed it in two weeks. So far for the good news.

The bad news is that, even if they only reattached a connector, they still wiped the phone itself. I had a backup from the backup application and a dirvish backup of /home/user

But obviously that's not enough. First of all, restoring from the backup takes a while - it reinstalled 110 apps, 20 of which stopped the installation because they feel I should click ok to install. Sigh.

Transferring 30 GB of old data is slow no matter which way you cut it.

I lost my Angry Birds levels and the Sygic Mobile Maps app, still trying to figure out if I can get those back easily.

But at the moment I'm mostly annoyed at my problems figuring out why I can't ssh as user@ to the N900 anymore.

So, here are the steps I took:

$ sudo gainroot
# apt-get install sysklogd
# vi /etc/syslog.conf
(uncomment the line that says: auth,authpriv.* /var/log/auth.log)
# vi /etc/ssh/sshd_config
change LogLevel to DEBUG3
# killall sshd
(doing /etc/init.d/ssh restart does not actually get the job done; neither does initctl stop sshd)
# tail -f /var/log/auth.log
(finally the log is there)
try and log in

Now the log tells me:
Apr 7 12:51:31 Nokia-N900 sshd[2266]: User user not allowed because account is locked

And a quick look at /etc/passwd shows ! as the password, meaning the account is locked out.

So...

# passwd user
(pick a password)

then try and log in again using ssh keys, and now it works.

I had no idea a user needed a password before being allowed to log in with ssh keys (not using the password).

After this, don't forget to set logging back to INFO lest you fill up your limited disk space with useless debug info.

I got my N900 back. The micro-USB port had broken off cleanly. Apparently that's a known thing. I brought it to a Nokia Support Centre and they fixed it in...

Ever since upgrading to Fedora 14 my desktop felt sluggish. It was more than the typical boiling frog kind of sluggishness, where you get the feeling everything's snappy just after you bought a new fancy computer and install it freshly with a recent OS, and over time performance slowly degrades until you wonder why computers are always so slow. Sure, it looks like Evolution, after a round of improvements in memory management, has gone back to being a memory hog. But this time, it was more. It would go through short phases of unresponsiveness and then come back. Load would be consistently around 1 or more, but for no apparent reason at all.

After a while watching top, I noticed a process called kslowd[xxx] jumping up and down in the top output regularly. The k says it's a kernel process. No idea what it is. Googling isn't very helpful to learn what it actually is, but it did put me on the trail because there are huge amounts of posts on sites and mailing lists about this process eating CPU time and slowing down the computer.

After a bunch of reading some post suggested it might be this patch by Dave Airlie, a name I recognize, to the kernel. I took the Fedora kernel src.rpm, spent a few minutes getting acquainted with Fedora's kernel spec layout de l'année, integrated the patch, rebooted, and voila. No more kslowd000 eating all my CPU.

I recently found this workaround which I'll try next time the kernel gets upgraded.

That still doesn't tell me what that kernel process is supposed to be doing (anyone up for a mandatory rule of having man pages for kernel processes too ?), so feel free to comment!

Ever since upgrading to Fedora 14 my desktop felt sluggish. It was more than the typical boiling frog kind of sluggishness, where you get the feeling everything's snappy just after...

I've been hacking on Paisley again recently since I found it I am not the only current maintainer. There is a branch on github from which a 0.3 release was recently made.

That's good news, because I didn't really need a new project to maintain. But I still have code I want to see land there, so I'm working on merging branches between launchpad, github, and some of my experimental svn branches here and there.

I had just implemented a cache for the object view mapping using couchdb-python's mapping.py and it turns out someone else was interested in adding memcache support to cache document lookups.

Some discussion started on a possible API, and I took a stab at a first draft over the past week.

Separately from that, I also took a CouchDB training course for work (together with Marek, one of our developers) ran by the Couchbase (company merger of CouchOne, formerly CouchIO (?) and Membase) people. That was a good training - but I digress.

At night Marek told me that they have some 300 lines of code that sadly reuses some classes from the current work codebase to set up and tear down test cases that work against an actual couchdb instance. He didn't feel like rewriting all that code to not use some of work's code just so that it could be contributed to Paisley for example. I felt I could do it in less than 100 lines, but he didn't seem to believe me.

So here I am after a magnificent Jose Gonzalez concert at the Palau de la Musica which is right around the corner from me, trying to write the caching code, and realizing I can't properly test it together with the change notification listener I wrote.

So while I was watching an episode of Breaking Bad, I wrote the setUp and tearDown code to do just that - start a couchdb instance on a random port, get the port, and connect to it.

It's probably not perfect yet (I do a busy loop for the creation and filling of the log file to read the port), but it worked for my simple test case. And it's 74 lines of code, including docstrings (which Marek for some reason does not believe in) and comments (which Marek also not believes in).

It's being worked on in this branch and I hope to land that in the paisley tree soon.

I've been hacking on Paisley again recently since I found it I am not the only current maintainer. There is a branch on github from which a 0.3 release was...

A few weeks ago my root hard drive died on the media machine at home. Time to do the upgrade dance on a new drive. I jumped from Fedora 11 to Fedora 14.

Boy was I in for a surprise display-wise - it felt like it was 2001 all over again.

I connect the media machine with an NVidia GeForce 6200 card and its VGA output to the big screen TV. That worked fine before, albeit with the proprietary NVidia drivers. I don't use the DVI output because I don't have a cable.

So, the monitor preferences only show resolutions up to 1024x768, when in Fedora 11 it had no problem doing 1920x1080. I tried to fiddle with some xrandr stuff adding modelines but didn't find anything that worked well. It was a bit of a pain too; you're supposed to be able to delete modes you added, but I just got

$ xrandr --rmmode "ATSC-1080-60p"
X Error of failed request: BadAccess (attempt to access private resource denied)
Major opcode of failed request: 149 (RANDR)
Minor opcode of failed request: 17 (RRDestroyMode)
Serial number of failed request: 27
Current serial number in output stream: 28

whenever I tried.

In the end I created a little script that made testing and adjusting mode lines easier for me, like so:

export DISPLAY=:0
export MODE="ATSC-1080-60p-5"

xrandr --newmode "$MODE" 148.5 1920 2000 2056 2200 1080 1082 1088 1125
xrandr --addmode VGA-1 "$MODE"
xrandr --output VGA-1 --mode "$MODE"

I tried to install the nvidia drivers from rpmforge. Sadly the latest kernel oopses on this machine (not sure yet why), and there were no built modules for the original Fedora 14 kernel release. After I realized that all older kernels are removed from updates and can be gotten from Koji, the build system, I was on my way to reboot into a working kernel with nvidia drivers installed.

Except that those only found 640x480 and 320x240 resolutions. And adding modelines using xrandr doesn't even work there.

Remove all nvidia drivers, reboot with a nouveau driver enabled, and tinker some more. None of the lines in this MythTV modeline database for Sonys actually worked. The ones I generated with cvt or gtf where displaced way to the right.

Eventually I stumbled upon this HTPC howto with an ATSC-1080-60p modeline that almost worked - the image was just slightly to the right. So, re-reading ESR's XFree86 modeline howto (after ten years or so ?) helped me do the final adjustments. Now just to make the settings permanent.

Of course, the proper fix would just have been to plug in a DVI to HDMI cable, and rely on EDID (which I assume works). Haven't bought the cable yet though. Neither my Sony TV nor my Sony amplifier have a DVI input, and I don't know of a way to pull in digital sound through a DVI to HDMI converter.

But I do wonder why the system was able to automatically detect and go to 1920x1080 in my previous (but broken) Fedora 11 setup...

A few weeks ago my root hard drive died on the media machine at home. Time to do the upgrade dance on a new drive. I jumped from Fedora 11...