My iMac (27-inch, mid-2010) crashed and refused to reboot. I was able to reboot it from an external drive and attempted to erase and resurrect the internal drive; after several attempts, the drive ceased to be visible to Disk Utility and am afraid it may be physically defective. Is there a way of mounting the disk and confirming its status?
I am seeking suggestions on what may be going in with an iMac I am currently troubleshooting, as it’s displaying behaviour I do not recall seeing before.  Short story  This iMac refuses to boot up. It gets the Apple logo, gets past the progress bar, and then gets stuck on the grey screen for about two minutes before rebooting itself. However, what makes this odd is that I can:   Start the iMac in Target Disk Mode and use it to successfully boot up other Macs. In doing so everything seems to work perfectly fine. Successfully boot the iMac from an external drive and everything seems to work perfectly fine.   Long story  I was presented this iMac about 2 weeks ago as it refused to bootup. That is, it would commence booting up and cycle through the Apple logo and progress bar, but after the progress bar completed it would remain on the grey screen for a couple of minutes before rebooting itself and doing the same thing all over again.   To address this I undertook the following troubleshooting steps:   Resetting SMC - failed Resetting NVRAM - failed Starting up in Safe Mode - failed Starting up in OS X Recovery Mode – failed Starting up in OS X Recovery Mode via the internet – failed Undertook an extensive hardware test using Apple Hardware Test (AHT 3A213) - passed Started iMac in Target Disk Mode and retested hard drive using Scannerz on another iMac - passed Started iMac in Target Disk Mode and reformatted the hard drive and did a clean install of Mac OS X El Capitan 10.11.6 - successful Migrated data from a Time Machine backup - successful   After these steps I tested the iMac for four days with no issues in terms of booting up and using the computer. On the fifth day I needed to manually import seven Apple Mail mailboxes. I did these one by one and six of them imported within minutes.  The last mailbox was showing as being 270 GB in size. I knew this was inaccurate, but I decided to import the mailbox so I could do a mailbox rebuild to correct whatever corruption had taken place. This import took over 12hrs to do but seemed to work fine and Mail was displaying the emails.  I then tested the iMac on and off for another day to ensure it had no problems booting up. This was successful.  I then decided to initiate the mailbox rebuild, but as soon as I did the screen went black and stayed that way regardless of any keyboard shortcuts I tried using. I waited an hour, forced a reboot, and ever since the iMac has returned to its original behaviour of not booting up – it would get past the progress bar and stay on the grey screen for a while before rebooting itself and starting the whole vicious cycle again.  I have again retested the hard drive, processor, RAM and Video Ram by starting the iMac from an external hard drive and using a combination of the following packages:   Apple Hardware Test (AHT 3A213) Scannerz TechTool Pro Memtester (under the Homebrew subsystem)   And now I have a situation where I can boot the iMac from external hard drives, and also use it in target disk mode to boot up other Macs, but cannot use it to boot from its own internal drive.  At present I have isolated the internal hard drive and am running a scan to check for any malware.   In the meantime, I am wondering:   Has anyone come across a similar scenario and, if so, what was the cause? Assuming I find no malware, do I go through the reformat/clean install/migration process again, but this time not import the last mailbox and see whether the iMac works fine? Any other suggestions?   iMac specs are as follows:   iMac (27”, mid 2011) 3.1 GHz Intel Core i5 8 GB RAM AMD Radeon HD 6970M 1024 MB 1 TB 3.5” SATA HD Mac OS X El Capitan 10.11.6
Inaccurate shading on object I am relatively new to Blender so please excuse me if this is rather amateur!   The bottom of my torus has poor surface quality, I have scaled the vertices down for a smaller (variable) tubular radius all the way around the torus and at the bottom the surface quality is awful, with inaccurate shading. Any ideas as to what is wrong and/or how I could fix this?  Thanks, itsanate I was wondering how to list all the hardware info in my computer?   Both terminal and GUI solutions please. Is there a single utility to monitor most hardware's working status? Just like some software in Windows?   Thanks and regards! How to auto populate with conditions? How do I remove a file named "NUL" on Windows? I have a Windows XP box (NTFS filesystem) on which I found a file named NUL. I have not been able to remove this file in any usual way. The file appears to be owned by Administrator in the SYSTEM group, unlike any other file in the same directory (the other files are owned by my user id).  How do I get rid of this file? Where did it come from? Training N classifiers for N labels vs one classifier with N labels I have a classification problem which is multi-label with N labels. I would like to know which method would be the better choice? Training N classifiers (1 for each label) or a single classifier which use K-hot encoding. I'm using a neural network for this with a softmax at the last layer. (Is there any chance that the softmax would cause a problem?) I'm using tensorflow for the model. Redirect the output using `sudo` I have a small question regarding using sudo with output redirect &gt;. To enable IP forwrding, someone can use the command:  echo 1 &gt; /proc/sys/net/ipv4/ip_forward   Executing this command will give permission denied as it requires root privileges. However, executing the same command with sudo gives also permission denied error! It seems that output redirect &gt; does not inherit the permissions of the preceding command echo. Is this right?  As a workaround I do:  echo 1 | sudo tee /proc/sys/net/ipv4/ip_forward   Is this the best way to do it? Am I missing something?  Please, note that this is an example and it applies to all commands that use output redirect. Overfull box and broken pagination with page that contains only section headings Help ID this plant, quite possibly a weed I found this plant near my South Indian home in , India. Most probably it could be some sort of weed. Anyhoo, is this plant of any medical or commercial value? Is it a remedy for something?   It has a white tap root with little veins off the main root It has a really small yellow flower It's leaves are similar to that of a clover, except for that it has three to five leaves        Merci d'avance!  (P.S. Forgive me if this is some very common plant that I should know about, I'm in 7th grade.) iPhone stuck on Connect to iTunes My iPhone is stuck on Connect to iTunes Screen (support.apple.com/iphone/restore iTunes logo and up arrow with lightning cable) I have Tried :-   Connecting it to iTunes and Updating, It updates Successfully.But on the same screen again   Restoring, It restores successfully.But on the same screen again  Tried Recovery Mode Screen Method and DFU method Tried Closing and Restarting iTunes Tried Deleting 'iPhone Software Update' folder in iTunes and Re-Downloding Updates    Nothing Works... Any Help will be appreciated Why wasn't Sauron invisible when he wore the Ring? When Sauron is shown killing Elendil and then being destroyed by Isildur he is clearly not invisible and he is wearing the Ring.  But any time Bilbo or Frodo put on the Ring they went invisible without fail.  Did the Ring change after Sauron was destroyed or is Sauron capable of controlling the rings power unlike anyone else? Integral of $\sin(e^t)dt$ Let $f(x) = \int_x^{x+1} \sin(e^t)dt$. Show that $$ e^x|f(x)| &lt; 2 $$ and that $$ e^xf(x) = \cos(e^x) - e^{-1}\cos(e^{x+1}) + r(x) $$ where $|r(x)| &lt; Ce^{-x}$ for some constant $C$.  I can do the first part easily. Integration by parts gives us $$ f(x) = \frac{\cos e^x}{e^x} - \frac{\cos e^{x+1}}{e^{x+1}} - \int_{e^x}^{e^{x+1}} \frac{\cos u}{u^2}du, $$ so substituting $\cos u = 1$ and $\cos u = -1$ gives \begin{align*} \cos e^x - 1 + \frac{1}{e}\left(1- \cos e^{x+1}\right) &amp;\leq e^xf(x) \leq \cos e^x + 1 - \frac{1}{e}\left(\cos e^{x+1} + 1\right)\\ -2 &amp;&lt; e^xf(x) &lt; 2 \end{align*} So that $e^x|f(x)| &lt; 2$.  I get stuck on the second part, though. From integration by parts, I have $e^xf(x) = \cos e^x - e^{-1}\cos e^{x+1} - e^x\int_{e^x}^{e^{x+1}} \frac{\cos u}{u^2}du$, so it reduces to showing that $$ \left|\int_{e^x}^{e^{x+1}} \frac{\cos u}{u^2}du\right| &lt; Ce^{-2x} $$ for some constant $C$. However, I always end up with a constant for $Ce^{x}$ rather than for $C$. I have an ex who has posted nude photos of me online in the past, linked to my online social media, and posted my full name and where I live. I am concerned he may do so again once he finds out I'm now in a PhD program (he's very jealous of any success I have), and may link to my school bio page, or worse.   Revenge porn is illegal in my state, and the case against him is currently pending. I have also gotten the photos taken down with a DMCA letter (I hold the copyright over the photos in question). At this point, I am concerned with how a future attempt could affect my career.  I can handle the embarrassment now that I've been through it once, so if that's the biggest concern, I can deal. I just don't want to lose a career over it, given how small academia really is and how a reputation might follow one around.  My question is, if I don't change my name (I've considered this, assuming I can keep him from finding out) and my photos are circulated and discovered by faculty or students, how likely am I to be thrown out of my PhD program or later lose a job as an untenured prof? Is a name change worth it?   (If it makes any difference, they are essentially just topless portraits; I'm not engaged in any sexual activity or anything weird, and were taken 10 years ago when I was very young and foolish.) On the mobile web after new privilege is earned, reputation block contains some design issues:   no margins poor text color inside bar         By tapping on "track the next one" link, page have been refreshed:   no margins empty block in the middle obscure content         Only after manual refreshing, page looks fine again:        It is hard to reproduce because you need to earn next privilege which takes a lot of time. But I believe it's no too hard for developers :) Prove that the equation $x^2-y^2 = 2002$ has no integer solution How can I search for special characters? Situation: It started out as me  for the literal string C-c in  but it ended up omitting the - sign and showing results which contained the strings C/C++ and C &amp; C++.  is an example of a post which contains that string of characters (yet fails to show up in the results).  Things I've tried:   post suggests that I can use the undocumented code: operator, but when I do that, it just wraps the whole term in double quotes like .  As @terdon in Unix &amp; Linux chat has , using this  does yield some relevant results, but it doesn't show me  that is supposed to be there. edit: It appears that the Symbolhound query no longer returns that result.  Finally,  says that you can search for literal characters, but as you can see:    Quoted phrases are exact matches except for case-sensitivity, for example, you can search  or .  The second example (symbols) leads to 0 results.  So by now I assume that the search engine has changed (but the old documentation still lingers on this site). Is there a method for me to search for strings that include special (or is it literal?) characters? Auto-incrementing field in feature class using ArcGIS Desktop? So I'm relatively new to ArcGIS and ArcCatalog.  I have created a field name of PROJECTID in a feature class in a Personal Geodatabase.  The data type is TEXT.  This will be a ten digit ID.  The first five characters will be a acronym.  The sixth character will be a digit that represents the type of feature.  It will be a number.  The last four characters will be numbers that should be incremented starting at 0001.    Example:     WATER-1-0001  Screen shot of the field:   So my question is how can I do this in ArcCatalog.  I've seen some Python code that will autoincrement like the following:  rec=[OBJECTID] def autoIncrement(a):   global rec   return "water" + str(a) + "-" +  format(rec, '04d')   Again I'm a newbie when it comes to ArcGIS . Now I am getting an error NameError name 'OBJECTID' is not defined. Full URL not working with php include I want to apply for Schengen visa, but employer NOC which is mandatory document for visa is not available with me I have resigned from my current company and will be joining a new company soon.   Hence, I cannot get a leave approval letter from my current company, and if I decide to join a new company and then request a NOC (No Objection Certificate) it will be late for visa process completion because of my traveling dates.   What can I show to the embassy as an alternative to this NOC document? Significant predictors become non-significant in multiple logistic regression I came across a combinatorial proof of the Fermat's Little Theorem which states that    If $p$ is a prime number then the number ($a$$p$-$a$) is a multiple of $p$ for any natural number $a$.  Let me write down the proof.    PROOF  We have pearls of $a$ colours . From these we make necklaces of exactly $p$ pearls .   First,we make a string of pearls . There are $a$$p$ different strings.If we throw away  the $a$ one one -coloured pearls  ($a$$p$-$a$) strings will remain.We connect the ends of each string to get necklaces.We find that two strings that differ only by a cyclic permutation of its pearls result in indistinguishable necklaces.But there are $p$ cyclic permutations of $p$ pearls on a string . Hence the number of distinct necklaces is    [($a$$p$-$a$)/$p$].  Because of this interpretation this is an integer.Thus ($a$$p$-$a$) is a multiple of $p$ for any natural number $a$. [HENCE PROVED]     MY CONFUSIONS    What is the use of the fact that $p$ is a prime in this proof?  If this proof is true then why is this not true for every positve integer $p$?