OpenWRT 101 (O'ReillyNet) [LWN.net]

OpenWRT 101 (O'ReillyNet)

Posted Jun 8, 2007 1:48 UTC (Fri) by sbergman27 (subscriber, #10767) [Link]

If you are looking for something cool to play with... something different than anything else that you have done in a while, I *highly* recommend picking up a $62 WRT54GL from Newegg or Amazon ($52 after rebate) and flashing it with OpenWRT.

16MB of ram and 4MB of flash may not sound like much.(!) But between the efficiency of the ulibc-based software and the amazing compression of the LZMA compressed squashfs filesystem, 4MB of flash seems more like a gigabyte of flash. And 16MB of ram seems more like 128mb.

I sometimes catch myself just staring at my router in awe-struck admiration. And I've had it since March! If you love a good blend of efficiency and functionality as I do, you'll love these little boxes.

Another nice piece of hardware is the Linksys WRTSL54GS. It, like the WRT54GL, comes with its own Linux based firmware out of the box, and is very well supported by OpenWRT. But it has 8MB of flash, 32MB of ram, and... drum roll please... a USB port. I use mine as a my network file server. Though I could equally well use it as a print server... or both. (I get about 12.5MB/sec raw throughput from the USB drive, and about 2.4 MB/sec transfer over the network via NFSv3.

Extensibility is what OpenWRT is all about. It uses ipkg for package management, and the web interface gives you point and click access to a whole plethora of officially supported packages, with even more available via 3rd parties.

I know I'm coming off like a sales brochure, but I honestly think that what these guys are doing is "Ice Hot" to cop a phrase from Doctor Who. ;-)

OpenWRT 101 (O'ReillyNet)

Posted Jun 8, 2007 9:01 UTC (Fri) by niner (subscriber, #26151) [Link]

IMHO even better than the Linksys models, are the ones from ASUS. I had an ASUS WL500G-Deluxe for 1 1/2 years and I know these moments of admiration, you described pretty well :) It has 200MHz, 32MB RAM, 4MB Flash and two USB2 ports.

I recently upgraded to the WL500G-Premium which now costs about the same (about 80 Euros here) and brings 266MHz, 32MB RAM 8MB(!) Flash and two USB2 ports. It's awesome what this little machine can do. I too use it as a file server. Brings me 3,5MB/s of transfer speed over the network :)
And I have still 2MB free space on the flash and it's getting hard to find something worth installing. I already have screen, ctorrent, nmap, iptraf (how cool is that?), tcpdump and even the huge nsupdate (the binary has 1,3MB!) for dynamically updating my DNS.

Downloading large ISOs via bittorrent over night with just 15W of power. It still exites me :)

I just hope that someone will manage to get the hardware crypto stuff working sometime. That would be just awesome, as that would spare me the old notebook doing VPN in our second office. The WL500G-Deluxe peaks at about 3MBit/s :(

But many, many thanks to the openWRT guys, you rock!

OpenWRT 101 (O'ReillyNet)

Posted Jun 8, 2007 16:05 UTC (Fri) by sbergman27 (subscriber, #10767) [Link]

Hey, could you post some more details about your set up? My WRTSL54GS has exactly the same processor running at exactly the same speed. And running OpenWRT Kamikaze with the 2.6.21 kernel, NFSv3 using the kernel space NFS server, and an rsize/wsize of 32768, I don't get that transfer speed. The limitation is definitely processor, as it sits pegged at 100% while transfering at 2.4MB/sec, and the NFS server thread is using 94%.

It sounds as if you are getting an almost 50% better rate and I'm very interested in why that might be.

Thanks,
Steve Bergman

OpenWRT 101 (O'ReillyNet)

Posted Jun 10, 2007 22:40 UTC (Sun) by niner (subscriber, #26151) [Link]

The only difference that comes to my head right now is that I'm still running whiterussian. Hope to come around to try kamikaze this week.

OpenWRT 101 (O'ReillyNet)

Posted Jun 8, 2007 15:21 UTC (Fri) by sdoyon (subscriber, #4221) [Link]

I have to recommend the WRTSL54GS. The USB port opens up all sorts of cool
possibilities.

Mine is acting as a streaming digital audio player, reading vorbis and
mp3 files from my PC over wireless NFS, and playing them out through the
little stereo in my kitchen. I've equipped the router with a cheap hub,
a so called USB soundcard, and a USB infrared remote control
receiver. It's kind of like a cheap Squeezebox without the LCD. It runs
the Music Player Daemon. 3 months uptime so far :-). 5000 songs in the
shuffle. I just love it.

OpenWRT 101 (O'ReillyNet)

Posted Jun 8, 2007 20:02 UTC (Fri) by DRBaldock (subscriber, #30881) [Link]

Do you know if the USB port(s) on these units will support a USB740 EVDO Modem, rather than the Ethernet port, as the Internet Uplink?

Thanks for any info,
David Baldock

OpenWRT 101 (O'ReillyNet)

Posted Jun 9, 2007 1:28 UTC (Sat) by DRBaldock (subscriber, #30881) [Link]

CORRECTION: I'm pretty sure the device is actually a USB720 EVDO Modem. (I was posting from memory when I was at work earlier.)

As far as toys go

Posted Jun 9, 2007 17:37 UTC (Sat) by man_ls (subscriber, #15091) [Link]

I have to say, I cannot recommend one of those things. I have a WRT54GL and it has seen very little use: yes, it has Linux and it runs busybox, but there is not much you can do with so little space. It still makes for a nice little router, but it doesn't connect directly to the ADSL line, so you need another gadget for that.

If you want to play, get an NSLU2 (or a "slug" as it's affectionately called by its happy owners), also from Linksys; also 32 MB of RAM, one ethernet, two USB ports, half the size of an WRT54GL. I received mine a couple of days ago (for about 80 ) and it has been much fun. Instead of a toned down version, you get to run Debian! That's right, the full distro; just flash it, plug an USB disk and get going. You still have a spare USB port if you want to use it as a print server. Or go with Gentoo if you feel like it, in fact you have a full-blown computer that consumes just 8 W; the list of applications is endless. If you already have a router and want something absurdly extensible, get one of these.

Sorry to sound like a competing sales brochure, but I'm honestly amazed too! :D

As far as toys go

Posted Jun 9, 2007 20:32 UTC (Sat) by sbergman27 (subscriber, #10767) [Link]

What kind of NFS/Samba performance do you get from the NSLU2?

As far as toys go

Posted Jun 9, 2007 21:16 UTC (Sat) by man_ls (subscriber, #15091) [Link]

I have measured more than 4 MB/s over the network using NFS, consistently, and it does not seem to be CPU-bound. This is using nfs-kernel-server, an in-kernel NFS.

With scp I get only 1.2 MB/s, and this time it is CPU-bound: the process eats more than 90% CPU. I haven't tried Samba yet.

As a print server it is really slow: sometimes it takes more than a minute to start printing, and gs is kept busy all that time. Keep in mind that the 266 MHz IXP processor is optimized for network performance, not for general computation; in my OpenSSL tests it is like 20-40 times slower than my desktop amd64 @ 2 MHz. So a task which takes 2 seconds here can consume over a minute on the slug. (I guess you, sbergman27, already know that, but other readers should take it into consideration.) Roughly like a 604 @ 166 MHz, for PowerMac veterans.

As far as toys go

Posted Jun 9, 2007 21:31 UTC (Sat) by sbergman27 (subscriber, #10767) [Link]

Thank you for the info. The cpu-boundness of the WRTSL54GS in file serving tasks seems to be in the networking code. ttcp with a blocksize of 32768 bytes gets me only 3.6MB/sec @ 100% cpu load when the router is the sender, and 5.0MB sec as receiver. This is over a 100mbit wired connection.

I've not tried my unit as a print server, so I may seem a bit naive here. But have you configured the queue as a raw print queue on the NSLU2 side and set the machine that the printing client is running on to do the actual work? There is really no need for the NSLU2 to be running gs is there, when cat would do?

As far as toys go

Posted Jun 10, 2007 0:09 UTC (Sun) by man_ls (subscriber, #15091) [Link]

But have you configured the queue as a raw print queue on the NSLU2 side [...]?

Hmmm, you are right. I was lazy and just set up the local machine to use the remote CUPS (via client.conf), instead of configuring a remote printer. Now I have done it properly and it prints as fast as local. Thanks!