Re: So why not create a new v2 compression scheme?
The "v2" question is addressed in the blog and the answer is quite simple: who gives a flying fuck about disc compression these days? You queue up the I/O and wait for DMA to deliver the data and then re-schedule the thread. Meanwhile, there's 101 other things the CPU can be doing.
Back in the 80s and 90s it probably meant something because: (i) there weren't 1001 other threads in the waiting queue, and (ii) the disc access probably wasn't a simple case of "send a few bytes to the controller and wait". Both factors meant that the CPU was probably kicking its heels whilst the I/O happened, so reading less data and burning the wasted cycles on decompression was a win.
These days, file-system compression is just making work for yourself (the compression) so that you can force yourself to do other work (the decompression) later.
Biting the hand that feeds IT
