bs in dd
 

I was trying to make my pendrive bootable. For that I found that "dd" will work. But I am not able to understand what does "bs=4M" mean ? What does it do ?

Please help me out!!

Well the 'dd' manual page says that 'bs means Bytes. Read and write BYTES bytes at a time (also see ibs=,obs=)'. I recommend you take a look at the manual page as a starting point.

It stands, I believe, for "block size" and seems to be the amount of data read and/or written in one operation.

It is also important for the 'count=' option. You specify the count in terms of 'bs'. So 'bs=1M count=1000' would write 1000 M in 1M chunks.

Also, a higher 'bs' usually leads to better performance. From my benchmarks 'bs=4M' or 'bs=6M' work best depending on your processor cache size and other factors.

Thank you guys !!
It was helpful !