Hacker Bike Ride

vic — Thu, 27 Jul 2006 20:49:29 +0000

I was up in Ottawa for about a week recently. I went there to attend the Ottawa Linux Symposium, do some work at the Ottawa office, hang out with my brother's family, and catch up with some of my Ottawa friends.

Of course, no Linux Symposium is complete without the annual Hacker Bike Ride. This ride has been happening for several years on the Sunday after the Symposium. Basically, a whole bunch of Linux geeks gather up some bicycles and take a ride around the city. It's an excellent social event, and the locals love to show off Ottawa's fantastic cycling and scenery to all the visitors from out of town.

This year's ride started from the usual Col By Dr. meeting place, and went straight up Sussex Dr. towards the Ottawa River. We followed Sussex Dr. past the Prime Minister's and Governor General's residences, and further east along the Rockliffe parkway. We looped back down the Aviation Parkway and along Hemlock to the Rideau River. Then we followed the Rideau River multi-use trail all the way up to Vincent Massey Park (near Hog's Back and Carleton University) for the annual "Linux in the Wild" BBQ hosted by the Ottawa Canada Linux Users Group.

After hanging out in the park for a while, eating lots of BBQ food, etc., the hacker Bike Ride continued over Hog's Back Falls to the Rideau Canal, and back downtown to where we started.

The evening continued with more bike geek goodness. Of course, it was the usual weekly HPVOoO gathering at the Vietnam Noodle House, followed by some bike swapping and a gelato run on Elgin St. There was a huge turnout, especially with a few of the OLS people that came by as well.

It's always fun to spend a day riding my bike around Ottawa. I'm also very happy with the Bike Friday folding bike I bought earlier this year. I love being able to take it with me whenever I travel.

Here are my photos from Sunday.

USB Mass Storage Devices (Compact Flash Card Readers) in Linux

vic — Wed, 27 Jul 2005 20:12:36 +0000

Presented to Ottawa Canada Linux Users Group (OCLUG), January 7, 2003.

Last updated: 2003/05/22 18:26:14. Please note that this document is several years old now. With most modern Linux distributions, your USB Mass Storage Devices should probably work automatically. Check your distribution's documentation.

Introduction

This talk is based on my own experiences using the following hardware andsoftware:

SanDisk ImageMate SDDR-75 CF/SM Card Reader
My parents' PC with Redhat 7.2
Home PC with Debian Unstable (my own kernel 2.4.18)
Work PC with Redhat 8.0
....with a slant towards using it for reading digital pictures

What is a USB Mass Storage Device?

"the driver is really an interface between the USB stack and the
SCSI layer"
- When you plug it in, a USB Mass Storage Device appears to be
  just another SCSI disk.
Examples:
- Compact Flash card readers
- Certain digital cameras
- "Keychain" hard drives
- USB CD-ROMs/floppies, etc...etc..

Why would you want to use the USB Mass Storage Driver?

To access USB mass Storage devices (of course)
Alternative way to access digital pictures (instead of gphoto2)
For digital cameras not supported in Linux (or not well supported)
- E.g. I can now upload files to my CF cards, which I cannot do via the Canon Powershot S40 driver in gphoto2.
- Use this for sending firmware upgrades to my camera
To conserve batteries in your digital camera
For using CF or SmartMedia cards as portable storage: Smaller and more convenient (if readers are available) than CDRW or Zip Disk
They generally work very well in Linux!

HOWTO:

The Easy Way!

If you have a relatively modern Linux distribution that is pre-configured to work with USB Mass Storage Devices (I've tested with Redhat 7.2 and 8.0), there's nothing you need to set up!. It should be truly "plug and play":

Plug your device in to the USB slot
It will be automatically detected by the kernel, and an appropriate entry in /etc/fstab will be added automatically.
The device will be mounted under /mnt/flash
Use it, just like any other storage device

Manual Setup

If you're running a Linux distribution that doesn't set up USB Mass Storage devices automatically, here are the steps you need to follow:

Configure the Linux Kernel:
- Add SCSI Support
  - SCSI Support (CONFIG_SCSI)
  - SCSI disk support (CONFIG_BLK_DEV_SD)
  - SCSI generic support (CONFIG_CHR_DEV_SG)
- Add USB Support
  - Support for USB (CONFIG_USB)
  - USB drivers. One or more of: ECHI HCD (CONFIG_USB_EHCI_HCD), UHCI (CONFIG_USB_UHCI), OHCI (CONFIG_USB_OHCI)
  - Preliminary USB device file system (CONFIG_USB_DEVICEFS)
  - USB Mass Storage support (CONFIG_USB_STORAGE)
Plug in your USB device. You should see your device listed in /proc/bus/usb/devices. If not, you need to fix the kernel or check your cabling.
Use the sg3-utils package to determine the device name of your USB Mass Storage Device:
- Install the sg3-utils package
  (e.g. apt-get install sg3-utils)
- List your raw SCSI devices by running sg_scan -i. The output will look something like this:

/dev/sg0: scsi0 channel=0 id=0 lun=0 [em]  type=5
MATSHITA  CD-RW  CW-7585    1.01 [wide=0 sync=1 cmdq=0 sftre=0 pq=0x0A]
/dev/sg1: scsi1 channel=0 id=0 lun=0 [em]  type=0
SanDisk   ImageMate CF-SM   0100 [wide=0 sync=0 cmdq=0 sftre=0 pq=0x0]
/dev/sg2: scsi1 channel=0 id=0 lun=1 [em]  type=0
SanDisk   ImageMate CF-SM   0100 [wide=0 sync=0 cmdq=0 sftre=0 pq=0x0]

This tells me that I have 3 SCSI devices on my system: My CD-RW drive, and two Sandisk ImageMate devices (it's a single hardware device, but the first slot is the CF card reader, and the second is the SM card reader)

Determine the real SCSI device associated with your USB Mass Storage Device with sg_map. The output looks like:

/dev/sg0  /dev/scd0
/dev/sg1  /dev/sda
/dev/sg2  /dev/sdb

Now we can match the results of these last two steps. For example my Compact Flash reader is on the /dev/sda device.

In most cases, USB Mass Storage Devices will only have one partition on them, so we can safely assume that the final, mountable device is /dev/sda1 (the first partition on /dev/sda).

Create a mount point for your device: mkdir /mnt/flash

Add an entry to /etc/fstab for this mount point:
/dev/sda1 /mnt/flash auto defaults,user,noauto 0 0

Now it's ready to go. Any user can mount the device:
mount /mnt/flash

Make sure you unmount it before taking the card out or unplugging it:
umount /mnt/flash

Other Stuff

Like any other "hard drive" device, you can run fdisk on it and play with the partitions:
fdisk /dev/sda
Format the partition(s) on the device, usually with a DOS/FAT filesystem, e.g.:
mkfs -t vfat /dev/sda1
...or with a journalled Linux ext3 filesystem (probably not useful when used with cameras, etc!):
mkfs -t ext3 /dev/sda1

vic.gedris.org - Linux