2009
07.09
07.09
2009
05.10
05.10
Sungjin Lee, Keonsoo Ha, Kangwon Zhang, Jihong Kim, and Junghwan Kim,
Link -> FlexFS: A Flexible Flash File System for MLC NAND Flash Memory,
To appear in Proceedings of USENIX Annual Technical Conference (USENIX ATC), San Diego, USA, June 2009.
what is Flex-OneNAND
benefits of Flex-OneNAND
| 3-chip MCP Solution | 2-chip MCP Solution | |
|---|---|---|
| memory combination |
 |
 |
| target application | Ultra High Density Device | 512MB ~ 2GB Navi. & Music Phone, DSC |
technical feature comparison
| items | OneNAND | MLC NAND (1) | Flex-OneNAND (2) (MLC Area) |
Flex-OneNAND (SLC Area) |
|
|---|---|---|---|---|---|
| product nature |
Bootability | YES | NO | YES | |
| P/E Cycle | 100K | 5K | 10K | 50K(TBD) | |
| ECC/EDC | 1bit ECC (2bit EDC) |
N/A | 4bits ECC(5bit EDC) | ||
| performance | Page Size | 2KB | 4KB | 4KB | 4KB |
| Read Performance |
108MB/s | 25MB/s | 67MB/s | 87MB/s | |
| Write Performance |
17MB/s | 4.4MB/s (1 plane) 8MB/s(2 plane) |
5MB/s(1 plane) | 15MB/s(1 plane) | |
note :
- (1) 50nm MLC(No cache), (2) 60nm Flex-OneNAND
merge performance comparison
Time delay of worst case during copy-back operating
worst case : Partially written two blocks are merged onto one free block
Flex-OneNAND feature highlight
| cost effective | Large Block Structure & MLC based NAND Core |
|---|---|
| enhanced performance | X16 Synchronous Burst Read/Write(66Hz) Superload/ Cache Program |
| reliability | Embedded automatic 4bit ECC, 5bit EDC |
| smart security | Normal OTP Block(128KB) and User Controlled 128KB OTP Block (1st Block OTP) |
| fixed pin count | 16 Address Pins Regardless of Density Increase |
| data protection | Three Stages of Data Protection (Lock/Unlock/Lock-Tight) |
| automatic boot up | Internal Boot Loader with 1KB XIP at Power Up |
| features | FBGA(LF)/ Bottom Boot Multiplexed Interface (Data-Address) available Operating Voltage 1.8V/ 3.3V |
| line-up | 4Gb, 8Gb(DDP), 16Gb(QDP) |
2009
05.10
05.10
Tolerating File-System Mistakes with EnvyFS
Lakshmi N. Bairavasundaram, Swaminathan Sundararaman, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
To appear in the Proceedings of the Usenix Annual Technical Conference (USENIX ‘09)
San Diego, CA, June 2009.
Available as: Abstract, Postscript, PDF, BibTex
2009
04.25
04.25
- ULFS(User-level Log-structured File System)
http://ulfs.sf.net
- LinLogFS
http://www.complang.tuwien.ac.at/czezatke/lfs.html
- NILFS
http://www.nilfs.org/
- Log-structured file system for Linux 2.6
http://aiya.ms.mff.cuni.cz/lfs/
- Wikipedia
http://en.wikipedia.org/wiki/Log-structured_file_system
2009
04.25
04.25
2009
04.25
04.25
- Title : Linux Multimedia Platform (LMP)
- Enviroments :
Linux Fedora Core 5
gcc
SDL- 1.2.11
IR Remote Controller
SAM7 Mini Board
- Screen Shots
2009
04.25
04.25
This is my first File System.
We wrote this paper in korean. 
################# INTRODUCTION #################
Hello, we are
students and studying FILE SYSTEM in UNINVERSITY OF SEOUL.Suddenly, we
decided to make a new file system. but we couln’t make a new file
system.We got a motivation from FAT. We solved some problems that file
system.Anyway We are developing new file system. please Be expecting
our new file system. thank you.
################ COMPILATION ################
It
has been test on linux kernel 2.6.15 of fedora core5. and we don’t know
that file system is able to compile on another kernel version.it’s
possible. please send mail to me if you compile on another kernel
version.
########## USAGE ##########
1. util/mkfat /dev/2. insmod src/fat.ko3. mount -t fat /dev/
############ TESTING ############
Our
file system is still testing on linux kernel 2.6.15 and has many bugs.
We have to modify these problems.It’s very difficult. If you catch bugs
in our file system, please tell me through e-mail.
############ CONTACT ############
1.ysoh@uos.ac.kr (OH YONGSEOK)
We are going to welcome to your message. Any message will be a good advice to us.Thank you for your reading.