How can one copy a file into HDFS with a different block size to that of existing block size configuration?

Yes, one can copy a file into HDFS with a different block size by using ‘-Ddfs. blocksize=block_size’ where the block_size is specified in Bytes.

How many blocks will be created in HDFS for a file size of 192mb?

Using the default block size of 128 MB, a file of 192 MB is split into two block files, one 128 MB file and one 64 MB file.

What is the different size of HDFS data block?

By default, HDFS block size is 128MB which you can change as per your requirement. All HDFS blocks are the same size except the last block, which can be either the same size or smaller. Hadoop framework break files into 128 MB blocks and then stores into the Hadoop file system.

Which HDFS command modifies the replication factor of a file?

xml configuration file is used to control the HDFS replication factor. Hdfs-site. xml looks like the following and you can change dfs. replication property to modify the default replication factor to all the files of HDFS.

Does all 3 replicas of a block executed in parallel?

By any case, not more than one replica of the data block will be stored in the same machine. Every replica of the data block will be kept in different machines. The master node(jobtracker) may or may not pick the original data, in fact it doesn’t maintain any info about out of the 3 replica which is original.

Why is HDFS block size so big?

Why is a Block in HDFS So Large? HDFS blocks are huge than the disk blocks, and the explanation is to limit the expense of searching. The time or cost to transfer the data from the disk can be made larger than the time to seek for the beginning of the block by simply improving the size of blocks significantly.

Why is a block in HDFS so large compared to disk block size?

HDFS blocks are large compared to disk blocks, because to minimize the cost of seeks. If we have many smaller size disk blocks, the seek time would be maximum (time spent to seek/look for an information). Thus, transferring a large file made of multiple blocks operates at the disk transfer rate.