Block or Buffer cache: It is a type of caching used in file systems for improving the performance of a file system. Here, blocks which are accessed again and again are put in memory. A hash table is used for locating a block in the memory.
Write-through cache: It is a type of caching in file systems where whenever data is written to a cache; it is copied immediately to the disk. Say, if a user is writing something, then this data is written to the cache. Now, if there’s a system failure then the data will be lost because it was written in cache and not in the disk. So, by using write-through cache the data will be immediately copied to the disk and even if the system fails, the data will not be lost.
Block read ahead: Block read ahead is a method for improving the performance of a file system. Here block are put in cache before they are required. This process is generally used for files which need to be read sequentially. It doesn’t work for random access files because it uses too much bandwidth.
Reduce disk arm motion: It is yet another method for improving the performance of a file system. In this method disk arm motion is reduced by keeping blocks which are in sequence in the same cylinder.