On 05/26/2015 06:46 PM, David T-G wrote:
% % Why are you preparing a dev-zero file in advance?
Because the time saving is enormous :-)
David, I don't think you understand how /dev/zero works. it not like /dev/random (which can block) or /dev/urandom. RTFM /dev/zero is like /dev/null. *ALL* it does is read zeros. The zero don't come from anywhere, least of all the disk so they will, by definition, be faster than any possible disk operation. in fact they are as fast as a basic system call, as fast as the kernel can fill the input buffer. So a big buffer on the 'dd' command will be much faster than a number of smaller one because it is the system call/return overhead that dominates. Try it and see. -- A: Yes. > Q: Are you sure? >> A: Because it reverses the logical flow of conversation. >>> Q: Why is top posting frowned upon? -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org