abstract:Flashcache is a disk cache component of Linux, developed mainly by Facebook since April 2010. It works by using flash memory, a USB flash drive, SD card, CompactFlash or any kind of portable flash mass storage system as a write-back persistent cache.
The flashcache is used to store frequently accessed data providing the fast data response found in solid state drives while the hard disk storage provides low cost storage.
Write caching would store data to be written on the HDD in flash memory initially until enough data was in the flashcache to do an efficient write to the HDD disks.