Log-structured file systems: There's one in every SSD | Hacker News Reader

Log-structured file systems: There's one in every SSD

lwn.net

48 pointslordgilman6 comments

Can a single post make you smarter? This was an awesome description of why log file systems match with SSD (as long as TRIM is part of the picture). It also covers how flash based memories work in practice (small reads, but block writes).

Very fascinating stuff for a guy that only does simulations software, but was once super curious about electronics in junior lab physics (nand gates, opamps, feedback circuits).

Great SSD video (the 24 raid 0 setup) http://www.youtube.com/watch?v=96dWOEa4Djs&feature=playe...

Valerie Aurora articles have gotten good reviews here before eg http://news.ycombinator.com/item?id=735982

An SSD is already like a raid 0. This is a Samsung block diagram of what's going on inside http://www.pcper.com/images/reviews/766/SSD-Samsung.png

You may want to get in electronics hacking ...

Look at some of this stuff for inspiration : http://www.ladyada.net/make/

I prefer not to hack just for hacking's sake, but to build something I need. For example, ATM I'm looking into building a bedside alarm light - an alarm clock that wakes you up with light. I would love one. The commercial models are stupidly expensive (169$ for a nice Philips model [1]). The electronics are pretty easy to replicate, I'm having difficulty with the case. Philips did an awesome job with theirs - great design and build. Actually, most DIY electronics suffer from the same problem : cases suck, because we just do not have the means of extruding plastic and the such. Maybe 3D printers will help.

[1] http://www.amazon.com/gp/product/B002CGSYPS

A reckon a battery backed RAM/SDD hybrid would be the fastest option available. I did search and found a 4G one that was selling for thousands of dollars (can't find the link now). They said that it could back up the whole of RAM to SSD in 60 seconds so the data security (with a reliable battery) would be pretty good. Should scale as well with the same amount of time required for more lots of 4G. I can't see any reason why this should have to cost so much though. 4G SSD + 4G RAM + Battery + Controller < thousands of dollars. Must still be in the 'paying for the innovation' stage I guess.

Acard (acard.com) sells battery backed RAM/CFcard solutions for well under $500. There are compromises. It will fit your budget, but may not fit your needs.

Thanks for that. This page has a clearer description than the companies web site.

http://2xod.com/articles/ANS_9010_ramdisk_review/

Seems like it wouldn't be too hard to build this into motherboards so you could essentially have non-volatile ram for whatever purpose you wanted.

Reply on news.ycombinator.com