such that you don't end up with so much slag that you blow the estimate. That means that to a first approximation, to construct a single maximally-sized ZFS pool out of the current largest-available microSD cards, you might have to use an entire Earth-sized planet's worth of atoms, and then only if you start off with something close to the right mix of silicon, carbon, gold, etc. We also need some slop here to account for inter-chip interconnects, etc.Ī pico- anything is 10 -12, so our 47 pg and 2.5×10 -13 g/B numbers above are about an order of magnitude apart. The density of data in grams is 2.5×10 -13 g/byte for microSD storage, as of this writing: the largest available SD card is 1 TB, and it weighs about 0.25g.¹ A microSD card isn't made of pure silicon, but you can't ignore the packaging, because we'll need some of that in our Earth-computer, too we'll assume that the low density of the plastic and the higher density of the metal pins average out to about the same density as silicon. We can write that number instead as roughly 10 38 bytes, which means in order to hit that limit, you'd have to have a single Earth-sized ZFS pool where every one of its 10 50 atoms is used to store data, and each byte is stored by an element no larger than 10 12 atoms.ġ0 12 atoms sounds like a lot, but it's only about 47 picograms of silicon. volume sizeĢ 128 bytes is effectively infinite already. ![]() Now let's discuss the practical import of each of those limits: Max. ![]() A filesystem based on arbitrary sized integers would have to piece each number together from multiple blocks, requiring a lot of extra I/O from multiple disk hits relative to a filesystem that knows up front how big its metadata blocks are. The speed hit from arbitrary precision arithmetic is bad enough inside a computer's RAM, but when a filesystem doesn't know how many reads it needs to make in order to load all of the numbers it needs into RAM, that would be very costly. If you want fast arithmetic, you use fixed-size words, period. There are exceptions, but these are usually mathematics-oriented DSLs like bc or Wolfram Language. This is why arbitrary-precision arithmetic is an add-on library in most programming languages, not the default way of doing arithmetic. The alternative is called arbitrary-precision arithmetic, but it's inherently slow. ZFS's limits are based on fixed-size integers because that's the fastest way to do arithmetic in a computer. What internally limits these things? Long answer ^ "Modern Software Experience : Webtrees - web genealogy".^ "Eastman's Online Genealogy Newsletter : WebTrees - a New Web-based Genealogy Program".^ "SourceForge blog : A new start." Retrieved.^ "SourceForge blog : Some good news: SourceForge removes blanket blocking".^ "SourceForge blog : Clarifying 's denial of site access for certain persons in accordance with US law".^ "PhpGedView forum thread : Future of PGV". ![]() ^ "PhpGedView forum thread : PGV blocked in Cuba, Syria, etc".The day version 1.0.0 of webtrees was released, Tamura Jones reviewed and compared Webtrees with PhpGedView. On 26 July 2010, a month before version 1.0.0 of webtrees was released, Dick Eastman, who publishes Eastman's Online Genealogy Newsletter, introduced webtrees as "the wave of the future." ![]() In late 2005 the first one, called Genmod, was created. webtrees is the second fork of PhpGedView. Webtrees is a fork of PhpGedView, it was created in early 2010, when a majority of active PhpGedView developers stopped using SourceForge ĭue to issues with exporting encrypted software. It is compatible with standard 5.5.1- GEDCOM files. It requires a web server that has PHP and MySQL installed. Webtrees is a free open source web-based genealogy application intended for collaborative use. Partial translations for Yiddish, Galician, Indonesian, Romanian, Serbian and Japanese. Arabic, Bosnian, Bulgarian, Catalan, Chinese, Croatian, Czech, Danish, Dutch, English (GB, US), Estonian, Finnish, French, German, Greek, Hebrew, Hungarian, Icelandic, Italian, Lithuanian, Korean, Norwegian (Bokmål and Nynorsk), Persian, Polish, Portuguese (BR, PT), Russian, Slovak, Slovene, Spanish, Swedish, Tatar, Turkish, Ukrainian and Vietnamese.
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