Want to listen to your iTunes music at home from work, a coffee shop, etc?

It takes two steps: setup an SSH tunnel and forward zeroconf (‘Bonjour‘) traffic.

If you do it my way everything is already installed on your Mac and, especially nice for you corporate folks, doesn’t require admin privileges.
Windows users, you’re not necessarily SOL but Windows doesn’t ship with what you’ll need.

I use this technique on Snow Leopard, but I think it will work on Tiger and higher.

• Enable SSH on your home computer.
  System Preferences->Sharing->Remote Logon
• Enable iTunes Sharing.
  Preferences->Sharing->Share my library on my local network
• Still from your home computer, browse to 192.168.1.1 (or whatever your router runs on) and enable SSH port forwarding if you haven’t already. This technique definitely won’t work without this step.
• Protip: Optionally, register your public IP with a free Dynamic DNS service so you only have to remember a single domain name.
• At your work machine, go to a terminal and use the following two commands:

  dns-sd -P "myTunes" _daap._tcp. local 3689 localhost 127.0.0.1 &
  ssh -N -f homeComputer -L 3689:localhost:3689

  The -N means non-interactive, the -f means go to the background.
  The -L xxx:hostname:xxx enables a tunnel on the iTunes sharing port (3689).
  homeComputer is your router’s public IP address, or the domain name you hopefully setup earlier.

• To clean up when you’re done, you can run a

  killall ssh dns-sd

Finally, if you’re cool enough to keep your music on a Linux machine, you can also use this technique with Firefly formerly (mt-daapd).

Posted originally for my personal reference, but since my Mac tips get lots of Google hits hope this is useful to you too.

Screen Sharing on Mac OS X Snow Leopard – very convenient to have built-in*, and I use it to logon to my Ubuntu server when the CLI doesn’t cut the mustard – infrequent, but it happens.

If you’re like me, you occasionally get an unexpected blank or white screen when you connect to your other computer. It turns out the mouse and keyboard pass through just fine but the display is all white. Fix it by getting info on Screen Sharing.app and ticking the ‘Open in 32-bit mode’ box.

* Technical addendum: I would be remiss to sing accolades of the VNC-based Screen Sharing without mentioning Microsoft’s [Citrix] Remote Desktop. It’s significantly faster than VNC due to some sweet implementation differences – to my knowledge when you connect to the Windows host it switches to a special display driver that sends small drawing instructions over the tubes that are subsequently recreated on your client. VNC, while open source and commensurately ubiquitous in Unix/Linux/Mac land, is not so smart and blindly sends a compressed image of the screen. Just sayin guys – Remote Desktop is awesome.

I really don’t like waiting, especially when I can avoid it. Therefore, when I got tired of waiting for my computer recently I did something about it.

On SSH and passwords

The average ssh logon time consumes what feels like 3-4 seconds on my 2007-era machines. The delay has worsened since Ubuntu 0910, which now retrieves system information on logon (in its default form, nearly useless to me). I really like the idea of seeing useful info at logon time, but bottlenecking logon – the most common act that happens – for multiple seconds is unacceptable. If you’re like me, just use your own script instead of landscape:

apt-get remove landscape-common

I banged out some bash that runs nearly instantaneously and shows only what I actually care about, and it only took some lines in .profile. simple version:

echo 'df -h' >> ~/.profile
PATH=$HOME/bin/

Finally for a really good one that totally pays for itself: think about how many times you type in a password. The net time saved by not having to spend a few seconds typing in your password each time is huge.

echo "PubkeyAuthentication yes" >> /etc/ssh/sshd_config

It’s called public key authentication in SSH, and it’s one of the best kept SSH secrets.

Just finished optimizing the page load time by recompressing several large JPGs that used to be part of every page that had a sidebar (i.e. most pages on this site).

Load times are down to an average of about .983 sec from about 1.8 sec before. Hooray for more speed.

RAID5, generally speaking, is a bad idea. Unless you have some very specific needs, RAID5 increases complexity, is more prone to hardware failure and administration errors, and does not automatically back itself up. If two RAID5 member drives fail at the same time, *all* your data is SOL. Individual drives, such as a bunch of externals, are probably a better choice for most people. And if two individual drives fail, you can still get data from the rest of them.

But people are nevertheless drawn to RAID5′s speed and size; it’s a great way to effectively have a freaking gigantic drive. It’s set and forget, easy to expand in the future (with some filesystems), and for reads is substantially faster than one drive. If one RAID5 drive fails, it’s an easy fix via drop-in replacement.

Some advice: when building a RAID array, use drives from different sources. Going different brands is probably a good idea, but caveat emptor: Company A’s 1TB drive will most likely not be the same ultimate size Company B’s. The available space will quite probably be skewed by a few KB or MB.

It should go without saying, but build your array only when you have all drives in hand. To more easily allow future expansion of your RAID, when it comes partition time shave a meg or so off your smallest drive. And when you decide to expand your array, buy a drive that’s the exact same model as one already in there. It will probably be cheaper than the newest model anyway.

To keep your bookmarks and RSS feed favicons looking shiny, I changed the onpaws.com favicon again. I was getting tired of the crusty current one which I made on a whim one day:

Passable at 64×64, but it always looked crummy at the more commonly seen 16×16:

After becoming intimately reacquainted with the various ways to disable Photoshop’s on by default selections and fill anti aliasing, I started with a 16×16 canvas this time, using the pencil tool and as per usual keeping the background transparent. This was a candidate:

But I’m happy with this new one for now- it retains the motif of circle + ‘p’ descender from onpaws -> op.

What do you think?

This post is originally from April 2007 and never got published. Here’s hoping I’ll never have to use it again. ~paws

Take a deep breath and relax. This is not bad luck. This is God’s retribution for your failure to back up your data. You are a bad person and you deserve this. Fortunately, there is a way for you to spite the will of God and recover your data anyway. Unfortunately, acts of contempt in this class usually require nerves of steel, and this stunt is no exception. Here is what you do:
Make a partition that is at least as big as your first partition was. You can make it larger than the original partition by any amount. If you underestimate, there will be much wailing and gnashing of teeth.
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-23361, default 1):
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-22800, default 22800): 13032

Command (m for help): w

Run dumpe2fs on the first partition and grep out the block count
Example:

% dumpe2fs /dev/sda1 | grep “Block count:”
Block count: 41270953

If you are uncertain about this value, repeat Step 1 with a bigger partition size. If the block count changes, then you underestimated the size of the original partition when you made your first guess. Repeat Step 1 until you get a stable block count.

Remove the partition you just created
Command (m for help): d
Partition number (1-4): 1

Make a new partition with the exact size you got from the block count. Since you cannot enter block size in fdisk, you need to figure out how many cylinders to request. Here is the formula:

(number of needed cylinders) = (number of blocks) / (block size)

(block size) = (unit size) / 1024

(unit size) = (number of heads) * (number of sectors/cylinder) * (number of bytes/sector)

Consider the following example, where a hard drive has been partitioned into four primary partitions of 1, 2, 4, and 8 cylinders.
disk /dev/sda: 16 heads, 63 sectors, 23361 cylinders
Units = cylinders of 1008 * 512 bytes

Device Boot Start End Blocks Id System
/dev/sda1 1 2 976+ 83 Linux
/dev/sda2 3 5 1512 83 Linux
/dev/sda3 6 10 2520 83 Linux
/dev/sda4 11 19 4536 83 Linux
fdisk provides the configuration information I need in the head of the output.

The unit size is 516096 ( 16 heads * 63 sectors/cyl * 512 bytes/sector ).

The block size is 504 ( 516096 / 1024 ).

The number of needed cylinders for the second partition is therefore 3 ( 1512 blocks / 504 ).

The partition table shows that this is indeed the case: the first cylinder is 3, the second 4, and the last is 5, for a total of three cylinders.

The number of needed cylinders for the third partition is calculated similarly: 2520 blocks / 504 = 5, which corresponds to 10 – 6 (plus one, since we are counting the 6th through the 10th cylinders inclusively).

Notice that this calculation does not work for the first partition because the block count is wrong ( 976 instead of 1008 ). The plus sign indicates that not all the blocks are included in the fdisk value. When you try the calculation ( 976 / 504 ) you get 1.937. Knowing that the number of cylinders must be an integer, you can simply round up.

Run e2fsck on it to verify that you can read the new partition.

Repeat Steps 1-5 on remaining partitions.

Remount your partitions. Amazingly, all of your data will be there.

Credit for thinking of this strategy goes to Mike Vevea, jedi sys admin and MGH’s finest.

One of the things I haven’t mentioned before is the exciting history of onpaws.com. The progress has steadily slid from lame, slow hardware to unreliable hardware to the current oldie…not to even mention the constant drop in hosting quality. However, many things about it have been free, and even educational. The benefits significantly outweighed the cost, so I still win.

Someday when I get money to spend on this kind of thing, I’ll get real hosting for onpaws.com. But in the meantime, I can rest happy knowing I’ve spent a total of ~$57 on the hardware running this website, and $0 on hosting. Not too shabby for a midnight side project.

Here is your length warning; this is a really long post. Like the rest of onpaws.com, I’m writing for myself first and everyone else second.

I then started my internship with the big software company everyone loves to hate, and moving across the country meant getting settled in an entirely new place. onpaws.com was put on hold while I got moved into a new house with new roomates and circumstances. This is why there has been such a long downtime. Sorry to my dedicated readers. (Do I have any?)

Currently, sweet new hardware turns the onpaws.com gear:
Pentium 1 133 MHz
64 MB RAM
1 GB HD IDE
833 MB HD IDE
Ethernet+BNC+something weird card
SoundBlaster 16
Generic Modem

I found this hot-hot-hot piece of computer ass next to a dumpster on the day I moved out of my corporate sponsored apartment. It was running an old copy of Windows 98 with some weird assortment of dance software that didn’t work. Desperate to get any kind of working solution I sucked it up and took her home. Plus, my masochist-in-residence enjoys playing with this stuff.

Getting anything interesting installed on this speed demon proved to be an adventure. I’ve never had to install an OS on a computer from the pre El Torito days. (That means the computer couldn’t boot from a CD – it’s floppy, HD, or the highway, baby.) Since nobody had a floppy diskette in the house, and I was definitely not going to actually plunk down cash for one, I had to transplant the HD into my existing desktop.

The stupid tower has half a motherboard inside and the other half on a case door. Incredibly awkward construction, unfriendly to the enterprising sort (me). Not to even mention the sharp edges.

Anyway, I managed to switch the drive and get a Debian base going on it via my El Torito-capable desktop. While I’m a Gentoo luser this box certainly doesn’t have the oomph for compiling any source, so this is my first Debian install. I’m sorry to say I’m not a huge fan so far, but its mostly because I’m used to Gentoo’s little quirks. Packages definitely install noticeably faster on Debian though. I swapped the drive back once Debian base did its restart, crossed my fingers, and success! Surprisingly, the kernel booted; I only had to modprobe the right networking driver and we were in business.

The next part was actually getting it to serve pages. I was going to go LAMP + WordPress like before, but after all was installed, the 5-6 second front page load just wasn’t cutting it. I’m using something a lot more lightweight: lighttpd+fastcgi+php5-cgi+mysql5+Nucleus.

Page loads are down to about 3 seconds here, and while they probably won’t get any better, but they’re a ton better than they could have been.

The future of onpaws.com involves dedicated hosting, but this requires dedicated $. Things will eventually get better, so please bear with me as the changes happen.

This guy gets it exactly right. The complete freedom behind the Internet is exactly what makes it so appealing, and I truly hope it stays that way forever.

Today the spotlight slides onto the history of early user interface design.

A certain Steve Jobs some time ago mentioned the history of fonts on the Mac at the Stanford Commencement 2005 speech. Rumors of Jobs’ insatiable egoism notwithstanding, he laid claim to the existence of font technology on all computers. Of course, he didn’t actually design the appearance of the fonts so much as facilitate their implementation on the Mac. The initial design work was left to Susan Kare.

Susan Kare certainly has carved out her place in the annals of user interface design. Fortunate enough to design the well-made icons for the original Macintosh, she probably contritubed more than anyone could truly foresee to the popularity of computers today. Icons were a daring metaphor in a 1980s world of “serious” text and terminals, but the risk was well worth the reward. Ask any computer user today how legitimate icon-based interfaces are and you’ll always get the same affirmation. Everyone simply likes pretty things, and even more so when they help them get things done in an intuitive way.

Kare’s font credits include Monaco and the nostalgic original iPod font (originally “Elefont“, now known as the demised Chicago) Command Key flower. Kare even worked for Microsoft too on early versions of Windows.

P.S. Mac still has a few cool quirks with its typography engine (checked up to 10.4.2). Try opening up TextEdit, switching to the Zapfino font, and typing…”Zapfino” of all things. Cool.