Month: June 2021

Enlarge / On-disk encryption is a complex topic, but this article should give you a solid handle on OpenZFS' implementation. (credit: Paul Downey / Flickr)

One of the many features OpenZFS brings to the table is ZFS native encryption. First introduced in OpenZFS 0.8, native encryption allows a system administrator to transparently encrypt data at-rest within ZFS itself. This obviates the need for separate tools like LUKS, VeraCrypt, or BitLocker.

OpenZFS encryption algorithm defaults to either aes-256-ccm (prior to 0.8.4) or aes-256-gcm (>= 0.8.4) when encryption=on is set. But it may also be specified directly. Currently supported algorithms are:

• aes-128-ccm
• aes-192-ccm
• aes-256-ccm (default in OpenZFS < 0.8.4)
• aes-128-gcm
• aes-192-gcm
• aes-256-gcm (default in OpenZFS >= 0.8.4)

There's more to OpenZFS native encryption than the algorithms used, though—so we'll try to give you a brief but solid grounding in the sysadmin's-eye perspective on the "why" and "what" as well as the simple "how."

Enlarge / University of Bonn physicists were inspired to investigate the aerodynamics of flying beer mats after traveling to Munich with a German physics demonstration show. (credit: sheck / iStock / Getty Images Plus)

Many a pub crawler has engaged in the time-honored tradition of throwing beer mats—those round cardboard coasters that are ubiquitous in bars—as if the mats were frisbees, often competing to see who can throw one the farthest. But unlike frisbees, beer mats tend to flip in the air and fly with a backspin. Now physicists at the University of Bonn have come up with a theoretical model to explain the phenomenon, according to a new paper submitted to the physics arXiv preprint server.

Thanks to their natural curiosity, physicists are fascinated by the physics of beer, and lead author Johann Ostmeyer is no exception. A couple of years ago, he became intrigued by the physics of so-called "beer tapping": a common prank where the perpetrator, holding an open bottle of beer, finds a target in the bar holding another open bottle. The prankster strikes the top of the target's bottle with the bottom of their own, then savors the sight of beer explosively foaming all over the target's hands and clothes.

Back in 2013, Javier Rodríguez-Rodríguez, a physicist at Carlos III University of Madrid, and several colleagues presented experimental and computer-simulation findings of why beer cans foam up so much after being shaken. They concluded that the foaming-over stemmed from a series of waves. Apparently the physics is similar to the development of the cloud in an atomic bomb, although the source of the "explosion" is very different.

Enlarge (credit: Getty Images | stockcam)

The Supreme Court today ruled in favor of a cheerleader and against the Pennsylvania high school that suspended her from the junior varsity team for a "vulgar" Snapchat post.

Brandi Levy was 14 in 2017 when she used Snapchat to express her frustration after failing to make the Mahanoy Area High School varsity cheerleading squad. Her Snapchat post contained an image of herself and a friend with middle fingers raised and the caption "Fuck school fuck softball fuck cheer fuck everything." A second post she made also complained about the varsity squad's decision but didn't contain any profanity. The posts were not widely distributed: as the Supreme court noted, Snapchat is "a social media application for smartphones that allows users to share temporary images with selected friends."

"B.L.'s posts expressed frustration with the school and the school's cheerleading squad, and one contained vulgar language and gestures," the ruling said. "When school officials learned of the posts, they suspended B.L. from the junior varsity cheerleading squad for the upcoming year."

Enlarge / John McAfee on his yacht off the coast of Cuba in 2019. (credit: Adalberto ROQUE / AFP / Getty)

John McAfee—the antivirus tycoon whose eccentric, larger-than-life, and often illegal antics on yachts and in tropical rain forests came to define him in later years—took his own life in a Spanish prison cell while awaiting extradition to the US. He was 75.

The death was first reported by El Pais and later by Reuters, both of which cited law enforcement sources in Barcelona. Multiple news agencies also reported the death.

According to El Pais, prison personnel found McAfee hanging in his cell and provided emergency medical services but were unable to save his life.