Building a low-power FreeNAS Server: Part 1

I've been looking into having a small file server in my home, to store my photographs and iTunes library. The most important aspects of that file server are, in order:

• Low power requirements: It is on 24/7 and I want don't want to consume too much power
• RAID-1: I want my data to be protected in case the hard disk crashes
  
• Low cost
• Good performance
  
• Expandability: Nice features such as a bittorrent client are a plus, I want to be able to experiment with DLNA in the future, so the "hackability" factor is important.
  

There were two contenders here that met most requirements: DLink's DNS-323 and Synology's DS-210j (Buffalo has some too but they are hard to find online). They each had a drawback: the DNS-323 is reported by many to be subpar in terms of performance, while the DS-210j is expensive.

So I decided to build my own NAS instead. It will most probably be based on FreeNAS, assuming it is hackable enough to my taste. The overall price is below the DS-210j, and I expect performance to be up to my expectations. Low power being paramount, I had to hand pick all the components and my next posts will detail what I've chosen, and how I'll be building it. I'll try to put some nice pictures.

O.

wuauclt.exe and svchost.exe taking memory on XP

Update 2010-08-21: The thread here indicates that Microsoft is investigating this as a priority 1 issue.

Normally I don't post PC and Windows-related stuff but there are not many recent posts on this August 2010 issue, so here it is.

I support my own PCs and those used by the extended family. For a few days a staggering issue has been happening. When configuring a Windows XP PC to use Microsoft Update (rather than the good old Windows update), svchost.exe and wuauclt.exe take so much memory that a low-memory PC (512Mb) will start swapping enough to freeze the whole system. I saw this happening on SP2 and SP3.

Yes, 512Mb is not a lot, but before calling me stupid, note that 512Mb used to be the standard configuration a few years ago for many low-end systems and it is officially supported by XP. That bug makes any low-memory PC unusable.

You should note that installing Microsoft Security Essentials switches any PC silently from WU to MU. That's how I introduced the problem and noticed it the first time on a laptop. I was about to reinstall it but found out that there have been some user reports here and here. Microsoft has not released a patch yet but I am sure many corporate users have stumbled on this problem and reported it officially.

The workaround in the mean time consists of connecting to Microsoft Update and choose to stop using Microsoft Update. The PC will revert to using Windows Update and everything will be working normally again.

O.

My top 2 articles on the internals of broadcom-based routers

Embedded devices are energy efficient, and their limited memory and storage present some satisfying challenges. How have I missed this for all these years, I don't know, but it is time to play catch up. For a few weeks, I've been spending some of my free time reading on Openwrt and the WRT54GL and other devices of similar design.

Of course, flashing a custom firmware can be daunting enough for an average user, but an average geek like myself will want to know how exactly these devices work. There is a published book on the subject but upon reading the table of contents, I decided against buying it as I deemed it not technical enough.

So, I assumed there was information somewhere for people like me, info that didn't require me to read source code. And there is, but you have to search for it.

And what are the top two articles I found on the subject? Here they are.

1. First of all, there is a three year-old post entitled "Everything you need to know about Broadcom hardware" here in the Openwrt forums: https://forum.openwrt.org/viewtopic.php?id=11304

It is extremely informative on the boot process of these devices and it finally clarified for me how the CFE bootloader works. I didn't understand the SquashFS + JFFS2 combination details, thanks to this post now I do. You also should read about union mounts if you're not familiar with the topic (I wasn't, HP-UX does not support this!).

2. Then you should read about how VLANs and network interfaces work on the Broadcom platform -- this article is from the old OpenWRT wiki but well done, too. It is specifically for the Asus WL-500g but being a Broadcom design I can only suspect other routers are very similar, if not identical:

http://wiki.openwrt.org/oldwiki/openwrtdocs/networkinterfaces

This article explains why you have a bridge interface on your router. It especially shines in explaining how these routers isolate the interfaces cheaply using VLANs. In fact, there is only one twisted pair interface (eth0), the other one being the wireless antenna (eth2). I was under the impression that firewalls needed different and isolated interfaces, but the VLAN trick lets you do something similar on cheaper designs. And I guess it is good enough!

I might replace my m0n0wall PC soon in order to reclaim real estate in my utility room and save a few bucks on electricity. I just need a router, and disable the wireless radio. But I will NOT be purchasing a WRT54GL. Why? I'll tell you in a future post!

O.

Ah, Mom, I bricked my router!

Remember I was running OpenWRT on a Bufallo WLI-TX4-G54HP ? After playing with OpenWrt a bit I spent some time setting up a Ubuntu-based build environment to be able to build my own custom firmware.

There's no particular reason for building a custom firmware since the package I want to ultimately run fits on the JFFS2 partition. I just wanted to get my hands dirty. But gasp... the documentation for OpenWRT is sparse and disseminated in four areas: an unfinished HTML manual, an old Wiki, a new Wiki being slowly migrated from the old one, and the OpenWRT forums. One really has to spend some time reading through all of them to understand how everything works, and I've covered maybe 10% of that. And that's okay. I don't pay a cent for OpenWRT and it's a distribution targeted to power-users... If I wasn't looking for a challenge, I'd be running Tomato instead.

Anyway. It turns out that I bricked my device yesterday after flashing that darn custom firmware. I didn't solder a serial or JTAG port, wasn't really looking into doing this, so I couldn't do much to troubleshoot. One thing that no longer worked, and this was supposed to be my planned way out, was the 2-3 seconds it pings on 192.168.1.1 when it's at the CFE bootloader so that I can TFTP a correct firmware. Since it no longer did this, I couldn't do that to unbrick it.

I was about to throw it in the garbage but found somewhere in the DD-WRT forums that some Buffalo routers listen to 192.168.11.1. I tried this address and it worked! Now as to why it decided to listen to 192.168.11.1 while the first time it was 192.168.1.1, I don't know. I must have pressed the reset button 50 times on this thing so who knows what it ended up doing.

Back to square one, I have a router that works, but no custom firmware.

O.

VMware player... what have I been missing?

Up until now, after all these years, I never considered using VMware Player because as its name implies, it used to be be a player for virtual appliances. That's what it was initially designed to do, but it looks like it can do much more than I thought.

Since I used to be an ESX admin, I don't feel the need to learn to use something else and the only solution I knew to virtualize random stuff for free on my low-end laptop, if I stuck with VMware's offering, was to use VMware Server. I tried Server a few times over the years, but must admit that it isn't really interesting when compared to ESX. The web interface is clunky, and it does not integrate well on a "home" PC.

Little did I know that versions 3 and up of VMware Player now let you create virtual machines at your liking, without needing to use pre-made appliances. I've tried it and it works well, and it is much easier to use than Server's web interface.

I've been "converted".

O.

Looking for my next technical venture

My regular readers know that I used to be an HP-UX admin until a few months ago, and I threw the towel on my sysadmin career.

I'm left with an interesting-enough IT-related job at work, but I can't blog about it easily. The work I'm doing cannot be easily contributed back in a generic way. And the technologies I'm learning are mostly specific industrial stuff and I don't think anyone would be interested in reading about this. Case in point: Is there anybody here, expect perhaps me, interested in IRIG-B ? Yeah, I thought so.

So I'm slowly investigating where I should spend maybe 2 hours a week learning the ins and outs of a new technical thing, and possibly start contributing to the community in whatever means I can, once I feel good enough with it (which might end up taking years). Since I work with embedded devices at work, I've been getting interested in the embedded market and it looks like my next venture might be with OpenWrt but as I don't have many practical uses for it at home, I'm still not sure.

I just found out that a smaller-than-netbook device named běn NanoNote went into production recently, and it runs OpenWrt. What is special with the NanoNote is that both the software and the hardware schematics are completely open designs. At 99$, it's as cheap as it can get. It's almost the same price as a dumb HP digital picture frame I purchased a few days ago, yet I can do whatever I want with it.


Whatever I want with it... I've been spending half an hour staring at the NanoNote specs and pictures, thinking about what I could use it for. Remember that it's very limited in memory and flash, and you can't fatten it up with thousands of bloated applications. In our iPhone/Android era, I simply don't know what people would think of this. But I'll admit it has one advantage against smartphones up its sleeves: it is cheap, and can be mass-produced unencumbered by patents and legal restrictions (at least, I think so).

One can only hope that someone smarter than me will invent a proper use for this device.

O.

What running backfire on a WLI-TX4-G54HP *really* looks like

The 10.03 release of OpenWrt is named "Backfire", which is a cocktail made of the following ingredients according to the login banner:

I happen to have these three drinks at home, so I fixed myself one to celebrate yesterday's experience with this device. Here's what it looks like, with a WLI-TX4-G54HP:

I thought it would have been a three-layer drink, but it gets mixed up quickly in tha glass. I never tried a Backfire before, and it does taste good. Both in the glass, and in the router.

O.