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From "Dr Mich Talebzadeh" <m...@peridale.co.uk>
Subject can block size for namenode be different from datanode block size?
Date Wed, 25 Mar 2015 15:11:08 GMT

Hi,

The block size for HDFS is currently set to 128MB by defauilt. This is
configurable.

My point is that I assume this  parameter in hadoop-core.xml sets the
block size for both namenode and datanode. However, the storage and
random access for metadata in nsamenode is different and suits smaller
block sizes.

For example in Linux the OS block size is 4k which means one HTFS blopck
size  of 128MB can hold 32K OS blocks. For metadata this may not be
useful and smaller block size will be suitable and hence my question.

Thanks,

Mich

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