How do I determine the best number to use for the bs (block size) operand of the dd command? Post: 303011890

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Top Forums UNIX for Beginners Questions & Answers How do I determine the best number to use for the bs (block size) operand of the dd command? Post 303011890 by Quenz on Thursday 25th of January 2018 05:28:23 AM

01-25-2018

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How do I determine the best number to use for the bs (block size) operand of the dd command?

When I create a bootable Linux distro installation USB drive, I use this command:

Code:

sudo dd if=/Path/to/linux_distro.iso of=/dev/rdisk<disk number>
 bs=<number of bytes>

When I look it up, I've seen variations of people choosing 4M, and I think 8M, 2M, and maybe even 1M.

If I leave the operand off, it seems to take a long time (I never let it finish).

How would I determine what number to use to make it go the fastest? Is speed the only factor?

Quenz

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