Michael StillGoogle Inc.October, 2006

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Linux on the Linksys NSLU2Solving all your problems

with little NAS boxes

Michael StillGoogle, Inc.October, 2006

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Who is this guy?

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What does he do at Google?

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Linksys NSLU2 NAS boxes

Consumer grade network attached storage

• 2 USB 2.0 ports

• 100 Mbit Wired Ethernet

• 133 Mhz processor

• 32 MB of RAM

• Cheap ($60 USD+)

• Linux

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Agenda

I want to cover:

• How to run your own Linux

• How to rescue yourself from a bad flash attempt

• Some ideas for projects involving NSLU2s

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How to run your own Linux

The process

• Download new firmware and upslug2 (the uploader)

– http://www.slug-firmware.net/s-dls.php

– http://sourceforge.net/project/showfiles.php?group_id=116564&package_id=164337

• Build upslug2

• Use the upgrade button pressing process

– http://www.nslu2-linux.org/wiki/SlugOS/UsingTheBinary

– You'll need a third arm here

• Run upslug2 with the new image, and watch it download

– sudo ./upslug2 -i path to firmware image from before

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How to run your own Linux

Demo of running UpSlug

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What did that give us?

DebianSlug

• A Debian install based on OpenSlug

– ipkg for package management

– Very small

– More limited package options

• Use turnup to bless a new root file system

– That can be a USB thumb drive or a USB hard disk

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What did that give us?

Demo of DebianSlug

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Debian Unstable

The next step is Debian Unstable

• Use the bootstrap process defined at:

– http://www.nslu2-linux.org/wiki/DebianSlug/Bootstrap

– Very slow

• Use turnup to bless the new root file system

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Kernel modules

There don't appear to be any Debian ARM kernel modules

• You need to use the pre-compiled ones from:

– http://www.student-zw.fh-kl.de/~pasc0010/debianslug/kernel-modules/kernel-2.6.16_preempt/

– Extract the package, grab the kernel module, and install it

wget URL to download

ar -x download.ipk

tar xvzf data.tar.gz

cd lib/modules/2.6.16/kernel/...

• Copy that to the slug, and don't forget to run depmod -a

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Recovering from a bad flash

My first attempt at flashing resulted in a brick

• It's really easy to recover though

• Download the Linksys firmware, and put it on a web server

sudo arping -f 192.168.0.1;

telnet 192.168.0.1 9000

• Now power cycle the slug

• You have two seconds to hit control-c to stop a normal boot

• You end up in RedBoot

– A network aware boot loader

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Recovering from a bad flash continued

My first attempt at flashing resulted in a brick

• Now download the firmware from the web server

ip_address -h 192.168.1.100

load -r -v -b 0x01000000 -h 192.168.0.100

-m http /NSLU2_V23R25.bin

fis write -f 0x50060000 -b 0x01060000

-l 0x7a0000

reset

• The slug will power cycle

• You're back at the Linksys firmware, and ready to try again

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Recovering from a bad flash continued

Demo of RedBoot

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Completely un-scientific testing

I am mainly interested in slugs as ATA over Ethernet NAS devices

• Compare performance of various firmware options

• Methodology

– Use postmark

set size 1000 9000

set number 2000

set transactions 50000

set location /mnt

set report verbose

run

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Postmark results

postmark will give you back results like this:Time:149 seconds total148 seconds of transactions (337 per second)

Files:27170 created (182 per second)

Creation alone: 2000 files (2000 per second)Mixed with transactions: 25170 files (170 per second)

24986 read (168 per second)24697 appended (166 per second)27170 deleted (182 per second)

Deletion alone: 2340 files (2340 per second)Mixed with transactions: 24830 files (167 per second)

Data:149.53 megabytes read (1.00 megabytes per second)161.85 megabytes written (1.09 megabytes per second)

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Permutations tested

Direct attached USB2

SMB using the Linksys firmware

SMB using DebianSlug

SMB using Debian Unstable

ATA over Ethernet using Debian Unstable

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Results

Create Create Alone

Create Mixed

Read Append Delete Delete Alone

Delete Mixed

0

500

1000

1500

2000

2500

Direct Attached USB2SMB LinksysSMB DebianSlugSMB Debian UnstableATA over Ethernet

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Results

Total time (seconds) Transactions sections0

20

40

60

80

100

120

140

160

Direct Attached USB2

SMB Linksys

SMB DebianSlug

SMB Debian Unstable

ATA over Ethernet

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Results

Data Read Rate Data Write Rate0

1000

2000

3000

4000

5000

6000

Direct Attached USB2

SMB Linksys

SMB DebianSlug

SMB Debian Unstable

ATA over Ethernet

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Other project ideas

There are lots of things you can do with low powered Linux machines with USB

• Car computing (with a USB wireless card)

• GPS data logging (USB GPS)

• Small sound player (with USB sound card and USB remote control)

• Lots of other things

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Questions?

Any questions?

I'll be putting these slides up online at http://www.stillhq.com when I get

back to Canberra tomorrow morning.

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One final note

Google is hiring, both domestically within Australia, and Internationally. Talk to me if you want to know more.

Michael StillGoogle, Inc.michaelstill@google.com