I received a trackback from Tim Bray’s Saving Data Safely post on the Android Developer’s blog to my Don’t fear the fsync! blog entry, so I guess the cat’s out of the bag.  Starting with Gingerbread, newer Android phones (starting with the Nexus S) will be using the ext4 file system.  Very cool!  So just as IBM used to promote Linux by saying that it was scalable enough to run on everything between watches and mainframes, I can now talk about ext4 as running in production on cell phones to Google data centers.

Richard Tibbetts has called me out for conflating Web 2.0 startups with all startups in my recent blog posting, “Google has a problem retaining great engineers? Bullcrap”. His complaint was that I was over generalizing from Web 2.0 startups to all startups.

He’s right, of course. The traditional “technology startup” by definition does have a large amount technology work that needs to be done, in addition to the business development work. However, things have changed a lot even for technology startups. Consider a company like Sequent Computer Systems, which started in 1983. At the time the founders had a key idea, which was to use multiple commodity intel CPU’s to create first SMP, and then later, NUMA minicomputers. But in order to do that, they had to design, build and manufacture a huge mount of hardware, as well as develop a whole new Unix-derived operating system, just to bring that core idea to market.

Once again, there’s been another story about how Google is having trouble retaining talent.   Despite all Eric Schmidt’s attempts to tell folks that Google’s regretted attrition rate has not changed in seven years, this story just doesn’t want to seem to die.   (And those stories about Google paying $3.5 million and $7 million to keep an engineer from defecting to Facebook?   As far as I know, total bull.  I bet it’s something made up by some Facebook recruiter who needed to explain how she let a live prospect get away.  🙂

At least for me, the complete opposite is true.   There are very few companies where I can do the work that I want to do, and Google is one of them.   A startup is totally the wrong place for me.   Why?  Because if you talk to any venture capitalist, a startup has one and only one reason to exist: to prove that it has a scalable, viable business model.   Take diapers.com for example.   As Business Week described, while they were proving that they had a business model that worked, they purchased their diapers at the local BJ’s and shipped them via Fedex.   Another startup, Chegg, proved its business model by using Amazon.com to drop ship text books to their first customers.  (The venture capitalist Mark Maples talked about this in a brilliant talk at the Founders Showcase; the Chegg example starts around 20:50 minutes in, but I’d recommend listening to the whole thing, since it’s such a great talk.)   You don’t negotiate volume discounts with textbook publishers, or build huge warehouses to hold all of the diapers that you’re going to buy until you prove that you have a business model that works.

Last night I managed to finish up a rather satisfying improvement to ext4’s inode and block allocators. The ext4’s original allocator was actually a bit more simple-minded than ext3’s, in that it didn’t implement the Orlov algorithm to spread out top-level directories for better filesystem aging. It also was buggy in certain ways, where it would return ENOSPC even when there were still plenty of inodes in the file system.

I came across the following from the ext3-users mailing list. The poor user was stuck on a never-updated RHEL 3 production server and running into kernel panic problems. He was advised to try updating to the latest kernel rpm from Red Hat, but he didn’t feel he could do that. In his words: I’m caught between a rock and a hard place due to the EMC PowerPath binary only kernel crack.

Dear Lazyweb, I’m looking for recommendations for Open Source backup solutions which track incremental backups using a database, and which do not use hard link directories. Someone gave me a suggested OSS backup program at UDS, but it’s slipped my memory; so I’m fairly sure that at least one or more such OSS backup solutions exist, but don’t know their names. Can some folks give me some suggestions? Thanks! There are a number of very popular Open Source backup solutions that use a very clever hack of using hard link trees to maintain incremental backups.

Given the recent brouhaha in Debian, and General Resolution regarding Lenny’s Release policy as it relates to Firmware and Debian’s Social Contract, which has led to the resignation of Manoj Srivastava from the position of Secretary for the Debian Project, I’m reminded of the following passage from Gordon Dickson’s Tactics of Mistakes (part of Dickson’s Childe Cycle, in which he tells the story of the rise of the Dorsai): “No,” said Cletus.

When I have a moment, I’ll try to tally up the responses that I got to “An ethical question involving ebooks”and see if there are any interesting patterns based on self-identified generational markers. Obviously, this is not a properly controlled survey, so the results aren’t going to mean much, but it is interesting that some fairly passionately written comments came from folks who self-identified as coming from generations that broke with the common stereotypes of their respective demographic groups.

With the price drop, I finally decided to get a 32GB iPod Touch, and I have to admit, Apple has done a really nice job. Its decisions about which applications it decides to arbitrarily blacklist from its AppStore (either now or without warning in the future) is evil, of course, but I don’t plan to develop on a locked-in platform such iPod/iPhone, so that’s not a problem. And of course, given AT&T’s evil customer service, I won’t be getting an iPhone any time soon (life’s too short to play cat and mouse with Apple’s cell phone locking games), this was probably my only opportunity in the short time to play with the iPhone/iPod touch’s e-mail application.

This wasn’t one of the things we were explicitly engineering for when were designing the features that would go into ext4, but one of the things which we’ve found as a pleasant surprise is how much more quickly ext4 filesystems can be checked. Ric Wheeler reported some really good fsck times that were over ten times better than ext3 using filesystems generated using what was admittedly a very artificial/synthetic benchmark. During the past six weeks, though, I’ve been using ext4 on my laptop, and I’ve seen very similar results.