APFS in Detail: Conclusions

This series of posts covers APFS, Apple’s new filesystem announced at WWDC 2016. See the first post for the table of contents. Summing Up I’m not sure Apple absolutely had to replace HFS+, but likely they had passed an inflection point where continuing to maintain and evolve the 30+ year old software was more expensive than building [...]

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Posted on June 19, 2016 at 12:37 pm by ahl · Permalink · Comments Closed
In: APFS, software

APFS in Detail: Data Integrity

This series of posts covers APFS, Apple’s new filesystem announced at WWDC 2016. See the first post for the table of contents. Data Integrity Arguably the most important job of a file system is preserving data integrity. Here’s my data, don’t lose it, don’t change it. If file systems could be trusted absolutely then the “only” reason [...]

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Posted on June 19, 2016 at 12:37 pm by ahl · Permalink · Comments Closed
In: APFS, checksums, RAID, software

APFS in Detail: Performance

This series of posts covers APFS, Apple’s new filesystem announced at WWDC 2016. See the first post for the table of contents. Performance APFS claims to be optimized for flash. Flash memory (NAND) is the stuff in your speedy SSD. Apple changed the computing industry when it put flash into the iPod and iPhone, volumes for which [...]

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Posted on June 19, 2016 at 12:36 pm by ahl · Permalink · Comments Closed
In: APFS, flash, FTL, NAND, performance, software, SSD, TRIM

APFS in Detail: Space Efficiency and Clones

This series of posts covers APFS, Apple’s new filesystem announced at WWDC 2016. See the first post for the table of contents. Space Efficiency A modern trend in file systems has been to store data more efficiently to effectively increase the size of your device. Common approaches include compression (which, as noted above, is very very likely [...]

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Posted on June 19, 2016 at 12:35 pm by ahl · Permalink · Comments Closed
In: APFS, snapshots, software

APFS in Detail: Encryption, Snapshots, and Backup

This series of posts covers APFS, Apple’s new filesystem announced at WWDC 2016. See the first post for the table of contents. Encryption Encryption is clearly a core feature of APFS. This comes from diverse requirements from the various devices, for example multiple keys within file systems on the iPhone or per-user keys on laptops. I heard [...]

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Posted on June 19, 2016 at 12:34 pm by ahl · Permalink · Comments Closed
In: APFS, software

APFS in Detail: Overview

Apple announced a new file system that will make its way into all of its OS variants (macOS, tvOS, iOS, watchOS) in the coming years. Media coverage to this point has been mostly breathless elongations of Apple’s developer documentation. With a dearth of detail I decided to attend the presentation and Q&A with the APFS [...]

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Posted on June 19, 2016 at 12:29 pm by ahl · Permalink · Comments Closed
In: APFS, software

ZFS: Apple’s New Filesystem That Wasn’t

Prologue (2006) I attended my first WWDC in 2006 to participate in Apple’s launch of their DTrace port to the next version of Mac OS X (Leopard). Apple completed all but the fiddliest finishing touches without help from the DTrace team. Even when they did meet with us we had no idea that they were mere [...]

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Posted on June 15, 2016 at 6:30 am by ahl · Permalink · Comments Closed
In: Apple, Mac OS X, ZFS

Finding What’s Next

After nearly nine years at Sun and then six at Delphix I’m looking for the next technology, team, and market to dive into. I’ve had the extremely good fortune of working with three groups—the DTrace team, Fishworks at Sun, and Delphix—that featured top-tier technologists working on differentiated products, each of them a wonderful place and [...]

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Posted on May 13, 2016 at 12:54 pm by ahl · Permalink · Comments Closed
In: SHV

Big News for ZFS on Linux

Canonical announced a few weeks ago that ZFS will be included in the next release of Ubuntu Linux, on by default and fully supported. And it’s no exaggeration when Dustin Kirkland describes ZFS as “one of the most exciting new features Linux has seen in a very long time.” In the words of our 47th [...]

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Posted on March 7, 2016 at 9:30 am by ahl · Permalink · Comments Closed
In: ZFS

Unikernels are unfit for production

Recently, I made the mistake of rhetorically asking if I needed to spell out why unikernels are unfit for production. The response was overwhelming: whether people feel that unikernels are wrong-headed and are looking for supporting detail or are unikernel proponents and want to know what the counter-arguments could possibly be, there is clearly a [...]

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Posted on January 22, 2016 at 9:48 am by bmc · Permalink · Comments Closed
In: Uncategorized