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Comment Something strange in the article. (Score 2) 68

FTA: Fragmentation in comets is rarely observed, but can occur when they are closest to the sun and develop spectacular tales of gas, dust and ice particles. The tale originates from the icy core (or nucleus), so when it heats up, vapor from sublimating ices are outgassed into space, dislodging dust and other material.

Shouldn't that be "tails" and "tail", or some different definition of the word "tale" I wasn't previously aware of?

Comment 50 years later... This is humbling. (Score 1) 175

You know, after working on my own long term project (25 years between updates), which Spacewar over-shadows by a factor of two, I've realized that code I write now, no matter how trivial, may be read back a long time afterward. And since I'm a very sloppy programmer, this is is embarrassing on a large scale.

Oh well. http://sites.google.com/site/dannychouinard/Home/rdos3-2-coco2-enhanced-dos if you're curious.

Earth

Model Says Religiosity Gene Will Dominate Society 729

Hugh Pickens writes writes "PhysOrg reports on a study by Robert Rowthorn, emeritus professor at Cambridge University, that predicts that the genetic components that predispose a person toward religion are currently "hitchhiking" on the back of the religious cultural practice of high fertility rates and that provided the fertility of religious people remains on average higher than that of secular people, the genes that predispose people towards religion will spread. For example, in the past 20 years, the Amish population in the US has doubled, increasing from 123,000 in 1991 to 249,000 in 2010. The huge growth stems almost entirely from the religious culture's high fertility rate, which is about 6 children per woman, on average. Rowthorn says that while fertility is determined by culture, an individual's predisposition toward religion is likely to be influenced by genetics, in addition to their upbringing. In the model, Rowthorn uses a "religiosity gene" to represent the various genetic factors that combine to genetically predispose a person toward religion, whether remaining religious from youth or converting to religion from a secular upbringing. Rowthorn's model predicts that the religious fraction of the population will eventually stabilize at less than 100%, and there will remain a possibly large percentage of secular individuals. But nearly all of the secular population will still carry the religious allele, since high defection rates will spread the religious allele to secular society when defectors have children with a secular partner."
Networking

Fedora 15 Changes Network Device Naming Scheme 132

dkd903 writes "Fedora developer Matt Domsch has announced that Fedora 15 is breaking the conventional ethX naming scheme used for Ethernet devices by adopting a new scheme called Consistent Network Device Naming. The ethX naming scheme works fine as long as the system has only one Ethernet port. However if there are more than one Ethernet ports, the actual problem starts."

Comment Re:They Why ZFS? (Score 1) 235

XFS is extremely prone to data corruption if the system goes down uncleanly for any reason. We may strive for nine nines, but stuff still happens. A power failure on a large XFS volume is almost guaranteed to lead to truncated files and general lost data. Not so on ZFS.

[Citation Needed] as wikipedia would say. XFS is no more prone to data corruption than any other journalled filesystem in the event of unexpected halts.

You should see the fireworks I got on Solaris 10 while I was running a script that did a bunch of zpool commands just as the power went out. Borked everything.

I love ZFS, but I'm not deluded into thinking it's magic.

Comment Luxury! (Score 1) 397

Luxury. We used to have to get out of the lake at six o'clock in the morning, clean the lake, eat a handful of gravel, work twenty hour day at mill for tuppence a month, come home, and Dad would thrash us to sleep with a broken bottle, if we were lucky!

Meanwhile I'm working on a micro-controller project that runs at 500Hz (not kilo, just hertz).

If you keep the code tight and hand-craft it, 128Mhz is blindingly fast.

Comment Easy problem to understand, hard to fix. (Score 1) 472

The problem is this: Let's say you do an action that reads 5 blocks on the disk. While the system is idle it has nothing else to do so your 5 blocks are read immediately, super fast.

While the system is doing some other I/O intensive job, it might be doing 500 block reads at the same time. Everything goes in the same queue, so your task is only %1 of the requests that have to be done in a set time. Result: Your task takes 100 times longer.

This is the problem that all the scheduler are trying to solve: trying to be fair so that every task gets a reasonable share of priority, while keeping performance at an optimum level.

For example, some O/S researchers have tried to implemented multiple-tiered system where every I/O is tagged with flags that indicate if the call came from an interactive user action, or was generated by non-interactive jobs (daemons, lower-level layers, etc...) and then give higher priority to the user requests. Two problems with that approach is it can be very hard to differentiate the two and that any heavy user task may prevent system tasks to work in a timely fashion and the user tasks may depend on the system tasks to complete their jobs in order to proceed; vicious circles and race conditions.

I'm glad I'm not trying to code a kernel scheduler, they're very hard problems and figuring one out that can be fair for all types of uses is nigh impossible.

The great thing about the open source O/Ss is that everything's done in the open, there's intense discussions going on about in the field, and there's multiple solutions being worked on and tested.

To me, Linux has always felt like it gave much higher priority to I/O than the "user experience". It's something I've come to expect. If I copy gigabytes from a disk set to another I gladly accept that my web browser's going to be sluggish for a time, all the while feeling content that at least it's going to be done so efficiently that it's going to last for the shortest amount of time possible.

Other O/Ss that I won't name may "feel" better, but have nowhere near the same I/O throughput that Linux has.

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