嵌入式Linux中针对掉电问题的数据保护技术研究

Research on data protection to power-off problems in embedded Linux

在实现嵌入式Linux过程中,会遇到文件系统损坏而导致系统无法正常启动的现象,针对这种情况,采用Linux初始化内存盘(INITRD)技术,把系统根目录建立在RAMDISK中,使Linux操作系统对文件系统的读写访问基本上都在内存中进行,降低了文件系统被破坏的可能性;然后又对这种方法进行了改进,提出了易破坏区瞬时挂载的方法,对易破坏区的写操作访问仅限制在系统关机时刻,而在操作系统运行期间易破坏区处于不可见状态,从而进一步降低了文件系统被破坏的可能性。

In the process of implementing embedded Linux, it happens sometimes that the system can not start normally because of the damage offilesystem. According to this, at first the technique of Linux initializing RAMDISK （INITRD） is used, which establishes root system in RAMDISK in order to make the operation of reading or writing the file system almost done in memory, and the possibilities of destroying filesystem are reduced. And then this technique is optimized. A method named instantaneous access to weak zone of filesystem is introduced. In this method, weak zone of filesystem is just accessed at the time of shutting down the OS, and it is invisible in the rest of OS running time. The possibilities of destroying filesystem are reduced further.