The two writing mode disk write-back & write-through

 

Back-wirte : the data written to the cache line, and then later to the disk brush;

through-the Write : Data is written to disk immediately, the other will be kept in a cache (used to enhance the read performance).

 

Remarks:

FIG cache buffer in file but not block (block), the block is the disk I / O unit is the smallest, Linux lower block size is typically 1KB.

 

advantage:

write-back: high performance disk write

Disadvantages:

wirite-back: when a system crash or sudden power failure, the data cache will be lost.