Development and Implementation of a File System for Gannet Virtual ...

Figure above shows the percentage of overhead process over different size of file.
However, there is tradeoff between space efficiency and time efficiency. Having a
large allocation unit tends to waste space as even a small file, a byte of file for
instance, will consume a single unit. However, the larger its size, the faster time
required to access each block as there is few blocks to proceed.
On the other side, having a small allocation unit means that a file will have many
blocks. Reading and writing operations quite slow as accessing each block requires a
processing time. Especially for writing operation, as there is a high overhead to
allocate blocks before writing data to the blocks.
The size of inode also has influence to the performance of read and write operations.
As discussed on section 2.1 , GannetFS file system is configurable. If the size of inode
is increased, the size of array of direct block on inode also increases. Hence, inode
can maintain more direct data blocks. This condition decreases the overhead which
resulted by indirect block.
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