filesystems - What is lazy space allocation in Google File system -

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i going through google file system (gfs) paper, mentions gfs uses lazy space allocation reduce internal fragmentation.
can explain, how lazy space reduces internal fragmetation?

source: http://research.google.com/archive/gfs-sosp2003.pdf

with lazy space allocation, physical allocation of space delayed long possible, until data @ size of chunk size (in gfs's case, 64 mb according 2003 paper) accumulated. in other words, decision process precedes allocation of new chunk on disk, heavily influenced size of data written. preference of waiting instead of allocating more chunks based on other characteristic, minimizes chance of internal fragmentation (i.e. unused portions of 64 mb chunk).

in google paper, says: "most chunks full because files contain many chunks, last of may partially filled." so, same approach applied file creation.

it analogous this: http://duartes.org/gustavo/blog/post/how-the-kernel-manages-your-memory


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