Whats the relationship between file system block size and disk space wasted per file

Question

1. What is the relationship between file system block size and disk space wasted per file.

2. How can reducing the file system block size could reduce the available/free disk space.

Answer 1

Its the CLUSTER SIZE that results in "wasted space." On hard file systems, disk space is allocated in clusters. Clusters are multiples of blocks. The block size is determined by the hardware.

The smaller the cluster size, the more clusters there are on the disk, the more overhead that is required to manage those clusters. Usually this is one or more bit maps with a bit per cluster.

Larger cluster size = lower overhead.

The tradeoff is that, if you need just one additional byte of storage, you have to allocate an entire cluster for it. The amount of "wasted" space grows with the size of the cluster.

Larger cluster sizes tend to be more efficient with larger files. Smaller cluster sizes tend to be more efficient with smaller files.