Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
HDFS >> mail # user >> Newbie question on block size calculation


Copy link to this message
-
Re: Newbie question on block size calculation
Seek time is ~ 10ms. If seek time has to be 1% of the transfer time then
transfer time has to be ~ 1000 ms (1s).

In ~ 1000 ms (1s) with a transfer rate of 100 MB/s, a block of 100MB can be
read.

Praveen

On Wed, Feb 22, 2012 at 11:22 AM, viva v <[EMAIL PROTECTED]> wrote:

> Have just started getting familiar with Hadoop & HDFS. Reading Tom White's
> book.
>
> The book describes an example related to HDFS block size. Here's a
> verbatim excerpt from the book
>
> "If the seek time is around 10 ms, and the transfer rate is 100 MB/s, then
> to make the seek time 1% of the transfer time, we need to make the block
> size around 100 MB."
>
> I can't seem to understand how we arrived at the fact that block size
> shold be 100MB.
>
> Could someone please help me understand?
>
> Thanks
> Viva
>