My hard disk drive stopped working. I have bought an external SATA to USB adapter and I have connected it and the disk makes noise and starts to spin. Nothing seems to be out of the ordinary. The computer detects it and opens the folder with the explorer, but instantly it stops working and does not detect it again until I disconnect and connect it again. What can the problem be? I’ve tried to put it in the fridge. Should I open it?
What steps can I take to try to recover lost or inaccessible data from any storage device?  Answers:   This applies to any computer storage device, e.g. internal/external hard drives, USB sticks, flash memory. The most important thing is to STOP using it, any type of I/O can ruin your chances of a recovery.     We have separate questions covering common problems with USB flash drives in greater detail:
Create database fields to an existing table when installing a module I'm new to drupal and I need some help.  I created a new module with name user_extra. Which create necessery table when Installing the module.  But I also need to insert some database field in 'users_field_data' table ('user_extra_id' and 'user_office')  In baseFieldDefinitions I wrote all necessery database table fields for user_extra table.   public static function baseFieldDefinitions(EntityTypeInterface $entity_type) {     // Standard field, used as a unique if primary index.     $fields['id'] = BaseFieldDefinition::create('integer')         -&gt;setLabel(t('Unit ID'))         -&gt;setDescription(t('The unit ID.'))         -&gt;setReadOnly(TRUE)         -&gt;setSetting('unsigned', TRUE);      $fields['uuid'] = BaseFieldDefinition::create('uuid')         -&gt;setLabel(t('UUID'))         -&gt;setDescription(t('The unit UUID.'))         -&gt;setReadOnly(TRUE);         .         .         .     $fields['user_info'] = BaseFieldDefinition::create('string')         -&gt;setLabel(t('User Info'))         -&gt;setDescription(t("The User Info"))         -&gt;setSetting('max_length', 255)         -&gt;setDisplayOptions('form', array(           'type' =&gt; 'string_textfield',           'weight' =&gt; 10,         ))         -&gt;setDisplayConfigurable('form', TRUE);      return $fields;      }   When I install the module it inserts all values that I define in baseFieldDefinitions.  But I also need to create 'user_extra_id' and 'user_office' in 'users_field_data' table with setDisplayOptions and setDisplayConfigurable options.  This is the commenting that I made in entity file  /**  * @ContentEntityType(  *   id = "user_extra",  *   label = @Translation("user extra"),  *   handlers = {  *     "storage" = "Drupal\user_extra\UserextraStorage",  *     "storage_schema" = "Drupal\user_extra\UserextraStorageSchema",  *     "access" = "Drupal\user_extra\UserextraAccessControlHandler",  *     "list_builder" = "Drupal\user_extra\UserextraListBuilder",  *     "view_builder" = "Drupal\user_extra\UserextraViewBuilder",  *     "views_data" = "Drupal\user_extra\UserextraViewsData",  *     "form" = {  *       "default" = "Drupal\user_extra\Form\UserextraForm",  *       "add" = "Drupal\user_extra\Form\UserextraAddForm",  *       "edit" = "Drupal\user_extra\Form\UserextraEditForm",  *       "delete" = "Drupal\user_extra\Form\UserextraDeleteForm",  *     }  *   },  *   admin_permission = "administer user_extra",  *   base_table = "user_extra",  *   entity_keys = {  *     "id" = "id",  *     "label" = "name",  *     "uuid" = "uuid",  *   },  *   links = {  *     "canonical" = "/admin/user_extra/{user_extra}",  *     "add-form" = "/admin/user_extra/add",  *     "delete-form" = "/admin/user_extra/{user_extra}/delete",  *     "overview-form" = "/admin/user_extra/${user_extra}/overview",  *     "edit-form" = "/admin/user_extra/{user_extra}",  *     "collection" = "/admin/user_extra",  *     "children" = "/admin/user_extra/{user_extra}/children",  *   },  * )  */ Derivative of function with 2 variables I've leart in Calculus 1 that the derivetive of $f(x)$ is:  $$\lim_{h\to0} \frac{f(x+h) - f(x)}{h}$$.  suppose $f(x,y)$ is a function with 2 variables,  does $$f'(x,y) = \lim_{h\to0} \frac{f(x+h, y+h) - f(x,y)}{h}$$ ?  If not , what is the derivetive of function with 2 variables? Problem using wildcard with apt When I run this command :  apt install libkf5*   I get the following error :  Unable to locate package libkf5*    I'm sure that the packages whose names start with libkf5 exist (tab-completion says so) . So the problem is not about the absence of those packages.(Note the asterisk at the end of that error message , the wildcard's not working at all) I use apt v.1.9. Thanks in advance. ISP blocking port 25 My ISP has started blocking port 25 so I can not send email through my dedicated server any more.   I have several options:   Send email through the SMTP server provided by my ISP. Any problems with this? Setup mu server so that it receives email on another port instead of port 25     No one else sends email through my server so it should be OK. How do I do this on a Linux server? Buy a static client IP - these are not being blocked so far.   Which one is preferable? Fade in each element - one after another I am trying to find a way to load a JSON page to display my content, which I currently have. But I am trying to fade in each element one after another? Is anyone familiar with a way to do that?  Fade in each element with a slight delay?  Here is an example of my code, I am using the jquery framework.  CODE: Why can't we see images reflected on a piece of paper? Is there a good Valgrind substitute for Windows? How to disable windows snap target In a fresh install of Windows 10 Pro. When I drag a window a snap target position image is displayed. See image.    This is very frustrating as the image is often displayed under the place where I want to place the window. The affect being that the window is therefore snapped and not placed where I intended it to be.  How do I disable this?  To be clear I don't want to disable snapping altogether just the annoying destination image underlay  UPDATE  I do not have the option to "Allow the system to suggest companion windows when using Snap" Let ${\rm f}:\left[a, b\right]\to\mathbb{R}$ be twice differentiable, and suppose   $$\lim_{x\to a^{+}} \frac{{\rm f}\left(x\right) - {\rm f}\left(a\right)}{x - a} = \lim_{x\to b^{-}}\frac{{\rm f}\left(x\right) - {\rm f}\left(b\right)}{x - b} =0 $$  Show that there exists $\xi \in \left(a, b\right)$ such that $\displaystyle{% \left\vert\vphantom{\Large A}\,{\rm f}''\left(\xi\right)\right\vert \geq \frac{4\left\vert\vphantom{\Large A}% \,{\rm f}\left(a\right) - {\rm f}\left(b\right)\right\vert} {\left(b - a\right)^{2}}}$.  I don't know how to start. Any hints ?. What happens in a circuit, when the wire and the battery are superconducting. And shorted I have seen the options such as a4paper, a5paper, letterpaper, etc... to go in the square brackets after \documentclass, but what I want is 8.25 inches width by 10.75 inches height for one document and 6 inches width by 9 inches height for another one. How is this done? What is the purpose of LongLength for .Net Arrays? Is there a way to transfer money and items from iOS to Android? I've been playing Jetpack Joyride on iOS, and I just got an Android device. Can I move my things, such as money and unlocks, from my iOS device to Android? Creating Inky-looking characters in Blender I'm involved in a project to do with ink animation and experimentation. I found this incredible piece of animation:    I originally thought this was some sort of After Effects compositing (is it even possible in AE?!), but found out that this particular animation was created in 3DS Max with Krakatoa and FumeFX. I'm just wonder if a similar effect is doable with Blender's smoke simulator.  There are various YouTube videos that have pretty decent results of ink renders from Blender, but I can't seem to find anything of a similar sort of movement animation. Just blobs floating around! The closest thing I found was this animation of a         but again I can't seem to replicate this. The smoke just doesn't seem to follow my character's animation. Any help with this would be greatly appreciated. Thanks. I am trying to slice up my models using the Boolean modifier.  After applying the modifier on my smooth mesh, I get the expected result, a flat dissection to separate my mesh into two.  The problem lies in how I can resolve the visual "jaggered" edge that separates my (smooth) mesh exterior from the flat dissection face.    Is it possible to achieve a smooth-to-flat variation without this artifact?   I tried to alter a mixture of the two but end up with artifacts, or unwanted blocky flat mesh faces around the dissection edge of my mesh. What is crop factor and how does it relate to focal length? What is the standard way to add N seconds to datetime.time in Python? Given a datetime.time value in Python, is there a standard way to add an integer number of seconds to it, so that 11:34:59 + 3 = 11:35:02, for example?  These obvious ideas don't work:  &gt;&gt;&gt; datetime.time(11, 34, 59) + 3 TypeError: unsupported operand type(s) for +: 'datetime.time' and 'int' &gt;&gt;&gt; datetime.time(11, 34, 59) + datetime.timedelta(0, 3) TypeError: unsupported operand type(s) for +: 'datetime.time' and 'datetime.timedelta' &gt;&gt;&gt; datetime.time(11, 34, 59) + datetime.time(0, 0, 3) TypeError: unsupported operand type(s) for +: 'datetime.time' and 'datetime.time'   In the end I have written functions like this:  def add_secs_to_time(timeval, secs_to_add):     secs = timeval.hour * 3600 + timeval.minute * 60 + timeval.second     secs += secs_to_add     return datetime.time(secs // 3600, (secs % 3600) // 60, secs % 60)   I can't help thinking that I'm missing an easier way to do this though.  Related Studying for an exam, a review question...  Given $G=\langle x,y|x^4=y^4=e,xyxy^{-1}=e\rangle$.    Show $|G|\leq16$.   For this, I want to consider that $x^3=x^{-1}$ and $y^3=y^{-1}$ based on our assumptions. I am a little lost as to how to put the second part, $xyxy^{-1}=e$ to show there are no more than 16 elements.   If $|G|=16$, find the center of the group and find a group that is isomorphic to $G/\langle y^2\rangle$.   I'm pretty sure the group is centerless. Block network access of a process? Understanding DNA match of 1,723 cM I have a DNA match of 1,723 cM with a male 6 years younger than me. His father is one of a twin, could my match be not my half-sibling but my 1st cousin.