I've been using dd for a couple of years now, most of the time successfully. I usually use it to dd Linux images to USB drives. My workflow doing so is as such:   convert .iso image to a .img format using hdiutil convert -format UDRW output.img input.iso unmount the drive using diskutil unmountDisk /dev/diskX dd the image to the drive using dd if=./image.img of=/dev/rdiskX bs=1m   Lately, and namely since I upgraded to Yosemite, dd has been showing some weird behavior. When I specify the block-size flag (bs=1m), it quits after about a minute, showing the default successful write message with the numbers of records in/out and bytes transferred and all that. What you would expect on a successful write. The problem is, it writes just a very small part of the image, then quits.  When I do not specify the block-size flag dd behaves as expected, writing the image to the disk in the ordinary fashion. Does anyone have any idea why this is happening?
Short version: In what circumstances is dd safe to use for copying data, safe meaning that there is no risk of corruption due to a partial read or write?  Long version — preamble: dd is often used to copy data, especially from or to a device (). It's sometimes attributed mystical properties of being able to access devices at a lower level than other tools (when in fact it's the device file that's doing the magic) — yet dd if=/dev/sda is the same thing as cat /dev/sda. dd is sometimes thought to be faster, but . Nonetheless, .  Problem: dd if=foo of=bar is not, in fact, the same as cat &lt;foo &gt;bar. On most unices¹, dd makes a single call to . (I find  fuzzy on what constitutes “reading an input block” in dd.) If read() returns a partial result (which, according to POSIX and other reference documents, it's allowed to unless the implementation documentation says otherwise), a partial block is copied. Exactly the same issue exists for write().  Observations: In practice, I've found that dd can cope with block devices and regular files, but that may just be that I haven't exercised it much. When it comes to pipes, it's not difficult to put dd at fault; for example try :  yes | dd of=out bs=1024k count=10   and check the size of the out file (it's likely to be well under 10MB).  Question: In what circumstances is dd safe to use for copying data? In other words, what conditions on the block sizes, on the implementation, on the file types, etc, can ensure that dd will copy all the data?  ( has a fullblock flag to tell it to call read() or write() in a loop so as to transfer a full block. So dd iflag=fullblock is always safe. My question is about the case when these flags (which don't exist on other implementations) are not used.)  ¹  I've checked on OpenBSD, GNU coreutils and BusyBox.
SE Android app for tablet has bad formatting on feed The lines wrap so much on v1.0.85 that only a few items can be displayed.  Edit: This is on the world's most low end tablet, Azpen A727.  Screenshots of the old:    and new, showing loss of quality At what stage should acknowledgements be inserted into the paper if review is not double-blind? When the review process is double-blind, I guess (although I have not read this anywhere) that acknowledgements should not be written in the submitted paper, as this might break anonimity. They should only be inserted into the camera-ready version, after the paper is accepted.  What is the custom when the review process is not double-blind? Should I write the acknowledgements in the submitted version, or wait to the camera-ready version? How to cross-reference an inequality with \cref? I have inequalities being cross-referenced by \cref as equations.  1-) How can I change that? (and still have inequalities with the same numbering as equations)  2-) How can I change that and have inequalities with their own numbering?  \documentclass[12pt]{article} \usepackage{amsmath} \usepackage{cleveref} \usepackage[letterpaper]{geometry} \begin{document}  \begin{flalign} &amp;f(x) \geq g(x)&amp; \label{i:positivity} \end{flalign}  Admitting that \cref{i:positivity} has a solution, ...    \end{document} What is the difference between confidence intervals and hypothesis testing? I have read about   with some commentators suggesting that hypothesis testing should not be used. Some commentators suggest that confidence intervals should be used instead.    What is the difference between confidence intervals and hypothesis testing? Explanation with reference and examples would be appreciated. Any good application for data usage monitor? I was wondering if there are any good applications to monitor how much data I use on my laptop in a month. My net connection has a restriction of how much data I can use after which the speed goes down considerably. I saw ntop, but I just wanted to ask if there are any other good options or suggestions regarding this. Regards. Objects with transparent texture not always show transparency in 3dview For some reason objects don't show their transparency all the time.  In this image the circles in red are suposed to be transparent like the ones in green.    When I select the object in the back, all objects in front of it become opaque.    When I select the two objects that are opaque, then they become transparent as they sould be.    The display is in GLSL mode  These are the material and texture properties      I'm not worried about the final render, just the editing view. I would like to see the actual transparency at editing time only, because the scene is to be imported in a third party game engine.  Blender is v2.68   is the blend file How can I write SQL for a table that shares the same name as a protected keyword in MySql? Why I think tension should be twice the force in a tug of war I'm going to provide my argument for why I think the tension in a rope should be twice the force exerted on either side of it.  First, let's consider a different example. Say, there is a person named A and a block in space. A pushes on the block with a force of 100 N. Then, the block will also push A with a force of 100 N by Newton's third law. Now, consider the case where instead of the block, there is a person B who is also pushing on A with a force of 100 N while A is pushing on him. A will experience a force of 100 N because he pushed on B, AND another 100 N because he is being pushed by B. Hence he will experience a force of 200 N. Similarly, B also experiences 200 N of force.  Now, back to the original problem. There are two people A and B in space with a taut rope (no tension currently) in between them. If only A is pulling and B is not, then I agree that the tension is equal to the force A exerts. This situation (in my opinion) becomes analogous to the above if B is also pulling. So, say both of them pull from either side with a force of 100 N. Then the rope at the end of B will pull B with a force of 100 N (this pull is caused by A). By Newton's third law, the rope will experience a pull of 100 N. But B is also pulling his end of the rope with 100 N. Therefore, the tension should be 200 N. Similarly, the end of the rope at A must pull A with 100 N of force (because B is pulling from the other side) and hence experience a force of 100 N itself by Newton's third law plus another 100 N because A is pulling on the rope.  Apparently, the answer is not this (according to my searching on the web). So, could anyone tell me why this reasoning is wrong? Thanks.  EDIT : So apparently people don't agree with my first example, leave alone the second. This is to the downvoters and the upvoters of the highest-rated answer: You all agree that if only A pushes B with a force of 100 N, then A and B both will get pushed by a force of 100 N in opposite directions, right? Then, in the case where B is also pushing with a force of 100 N, it doesn't make sense that the answer would be exactly the same. It doesn't seem right that no matter what B does, B and A will always experience the same force as they would have if B hadn't applied any force.  EDIT 2 : I'm going to provide here a link to a question that I posted:  According to the answer and the comments there, the reason as to why my first example is incorrect is different to the one provided here. So maybe you should all read the answer and the comments provided by the person and reconsider what you think. Does this double sum $\sum_{m=0}^\infty \sum_{n=0}^\infty \frac{m+n+mn}{2^m(2^m+2^n)}$ converge? Is it worth cleaning the registry? I have heard that you should keep the registry clean on Windows. Is this actually important or is it just myth? $\textit{Why}$ the cases in 4 $\nmid n^2 - 3?$ (bases cases in modular induction) This question has already been answered . My question is, when we suppose the hypothesis is not true (proof by contradiction), namely that $4 \mid (n^2 - 3)$, we get $n^2 - 3 = 4k$ for some integer $k$ and then we have two cases. But where does the two cases come from? In addition, why does putting them into two cases work to prove the statment? My thought process would be to try to prove this statement by contradiction and somehow figure out a way to produce a contradiction similar to how $\sqrt{2}$ is proved by contradiction. Any help is great! Let me know if I need to clarify more! How do I achieve this kind of light star effect? I'm kinda new to Blender. Currently playing around with version 2.8 to practice some rendering. Is there a way to achieve this 'light-star' effect for the blooming objects with the emission? If there is an alternative way then it's fine too. See these images below for references. Thanks in advance: I have been playing for almost 2 days, and today it is asking me to sign up again.  I have all my game saved in my google account, but I wonder if I just log in from a trainer account will I keep my progress? adjective describing middle distance (neither near nor far) How to find Windows 7 File Transfer History? Can decimal numbers be considered "even" or "odd"? With the advent of the WordPress Answers Stack Exchange site, there's undoubtedly going to be overlap.  But I just want to get some advice:  I'm a developer and I kinda hate WordPress, but have to use it occasionally. My WordPress questions are usually development ones (when I have them), and most often related to 'how WordPress handles things', which are pretty obvious in straight programming terms.  But with the WordPress layer of abstraction, they become problematic.  I find that most developers that have gone near WordPress are usually also PHP/JS/CSS/MYSQL guys who dabble with WordPress and, as a result, hangout more on SO. And theres a die hard bunch who are heavy into the WP.SE site, but generally the WP site is for people trying to muddle through the day to day operation of using WordPress and its many themes/plugin etc.    As a result, if I were to ask something pretty in-depth about writing / integrating new &amp; strange features or something, I'm talking to a much smaller group of devs than I would be on SO.  So, enough of the ramble, my question:  Should I be posting heavy development questions relating to WordPress on the WP.SE site or to SO? Can I post to both, or is cross posting frowned upon in these cases still? How to Create Bootable Windows 10 image in Debian? Pseudocode but originally developed for Windows 7 iso file but applied for Windows 8 in the thread  but it does not work with Windows 10 iso  # https://rwmj.wordpress.com/2010/11/04/customizing-a-windows-7-install-iso/ # https://unix.stackexchange.com/a/312477/16920 $ dd if=../en_windows_10_x64_dvd.iso \     of=boot.img bs=2048 count=8 skip=734  $ mkisofs -o ../new-win.iso -b boot.img -no-emul-boot -c BOOT.CAT \     -iso-level 2 -udf \     -J -l -D -N -joliet-long -relaxed-filenames .   Unsuccessful output when run on Windows 10 image  dd if=/home/masi/Downloads/en_windows_10_multiple_editions_version_1511_x64_dvd.iso of=/home/masi/Downloads/boot.img bs=2048 count=8 skip=734 8+0 records in 8+0 records out 16384 bytes (16 kB) copied, 0.000392973 s, 41.7 MB/s    Some of the following fields have changed for the iso file used in dd   bs=2048 count=8  skip=734   How can you study which field values you can use for Windows 10 iso?  OS: Debian 8.5 64 bit Hardware: Asus Zenbook UX303UA Linux kernel: 4.6 of backports Related threads: ,  Motivation: I need Windows 10 to use Canon P-150 duplex scanner, but when I started my Windows, I got Error 0xC0000428 because Windows update has again broken things there and I use Windows otherwise so rarely; and I have no spare Windows left to make bootable media How can I install packages without starting their associated services? As you're probably aware, by default when you install a package on a Debian or Ubuntu based system, if the package contains a service, that service will generally be enabled and started automatically when you install the package.  This is a problem for me.  I've found myself needing to manage templates for building LXC containers. There are several containers, each corresponding to a Debian or Ubuntu release. (There are also Red Hat-based containers, but they aren't relevant here.)  /var/lib/libvirt/filesystems/debian6_template /var/lib/libvirt/filesystems/debian7_template /var/lib/libvirt/filesystems/ubuntu1004_template /var/lib/libvirt/filesystems/ubuntu1204_template   Occasionally I will find that the templates have a missing package or need some other change, so I will chroot into them to install the package. Unfortunately when I do that, I wind up with several copies of the package's service running!  By way of example, I found the templates didn't have a syslog daemon, so I installed one:  for template in /var/lib/libvirt/filesystems/{debian,ubuntu}*_template; do     chroot $template apt-get install rsyslog done   And promptly wound up with four copies of rsyslog running. Not to mention two copies of exim4. Oops!    I read somewhere (though I can't find it again now) that it's not supposed to start services when running in a chroot, but that clearly isn't happening here.  One potentially viable  calls for temporarily replacing the various commands which actually start services, such as start-stop-daemon and initctl, though this is a lot more work than I really wanted to do. If I have no other choice, though...  The ideal solution here would be for Debian-based systems to stop doing this crap, but failing that, perhaps an obscure or undocumented command line option for apt-get?  In case it wasn't clear, I really want to keep anything related to managing the templates outside the templates, if possible. Prove that the natural map $\alpha : \text{Hom}(X,\text{Spec} A) \rightarrow \text{Hom}(A,\Gamma(X,\mathcal{O}_X))$ is an isomorphism This is question 2.4 in Hartshorne. Let $A$ be a ring and $(X,\mathcal{O}_X)$ a scheme. We have the associated map of sheaves $f^\#: \mathcal{O}_{\text{Spec } A} \rightarrow f_* \mathcal{O}_X$. Taking global sections  we obtain a homomorphism $A \rightarrow \Gamma(X,\mathcal{O}_X)$. Thus there is a natural map $\alpha : \text{Hom}(X,\text{Spec} A) \rightarrow \text{Hom}(A,\Gamma(X,\mathcal{O}_X))$. Show $\alpha$ is bijective.  I figure we need to start off with the fact that we can cover $X$ with affine open $U_i$, and that a homomorphism $A \rightarrow \Gamma(X,\mathcal{O}_X)$ induces a morphism of schemes from each $U_i$ to $\text{Spec} A$ and some how glue them together. But I have no idea how to show that the induced morphisms agree on intersections. How does this work?