最近在一台很久不用的电脑上安装了体积很小的Puppy linux，硬盘是去年买的一块2G TF卡，通过SD卡套+CF适配器+IDE转接卡接到 硬盘IDE口上。机器完全没有噪音，风扇基本不转。puppy 是直接解开文件系统后安装到硬盘上的，让人比较担心的是硬盘灯4秒钟要闪一下，反复读写对TF卡寿命也许有影响。前两年在jornada的SD卡上安装720degree 也一直有这个问题。
经过一番搜索后看到维基百科上的这篇文章。
这些闪存卡在硬件级别有wear levelling的，即使采用传统的ext fat 文件系统，也问题不大。
http://en.wikipedia.org/wiki/NAND_flash#Flash_file_systems
[edit] Flash file systems
Because of the particular characteristics of flash memory, it is best used with either a controller to perform wear-levelling and error correction or specifically designed flash file systems, which spread writes over the media and deal with the long erase times of NOR flash blocks. The basic concept behind flash file systems is: When the flash store is to be updated, the file system will write a new copy of the changed data over to a fresh block, remap the file pointers, then erase the old block later when it has time.
In practice, flash file systems are only used for "Memory Technology Devices" ("MTD"), which are embedded flash memories that do not have a controller. Removable flash memory cards and USB flash drives have built-in controllers to perform wear-levelling and error correction so use of a specific flash file system does not add any benefit. These removable flash memory devices use the FAT file system to allow universal compatibility with computers, cameras, PDAs and other portable devices with memory card slots or ports.
sandisk的 whitepaper
SanDisk Flash Memory Cards Wear Leveling. Page 2. SanDisk ... Current SanDisk products do not preempt wear leveling events during normal operation of the ...
www.sandisk.com/assets/file/oem/whitepapersandbrochures/rs-mmc/
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