LFS: read and write
Every write causes new blocks to be added to the current segment buffer in memory; when that segment is full, it is written to the disk
Reads are no different than in Unix File System, once we find the inode for a file (in LFS, using the inode map, which is cached in memory)
Over time, segments in the log become fragmented as we replace old blocks of files with new block
Problem: in steady state, we need to have contiguous free space in which to write