I have an external 1.5TB hard-drive which I've been using for years, no back-ups.   I have several partitions on that hard-drive, one of which has all my data on (I cannot remember whether FAT32/NTFS), and another bootable partition.  I attempted to install UbuntuStudio via Startup Disk Creator, I incorrectly assumed it would only write to the mounted bootable partition. Once I realised my mistake I clicked cancel, Startup Disk Creator crashed and I killed the program.  Now all of my partitions bar the 'UbuntuStudio' created partition have disappeared. The operation only lasted a second, I am hoping my data is recoverable.  I followed: , which showed a list of partitions not able to be recovered, and some which could be. From the partitions of which I could list files, none were my data partition. There were two partitions of identical size (about 200GB) which I could not list the files of. I know the 'label'/name of my data partition, if only I could search for it.  I'm on the verge of despair here, bar committing a crime - I'm sure the Police would have no trouble recovering my data - I don't know what to do. To whoever helps, I owe my sanity to you.  Note: I would post my logs, but I made a further mistake of closing testdisk - the operation took about 12 hours.    To my knowledge my HDD is not 5.45 TiB, it is ~1.5 TB.  Any method which repairs the partition records in place is ideal, I do not have a separate external HDD for backing up my files.  Update: this is what I see:    Update:    Scan has finished, I would like to attempt to Add Partition using data from the screenshots, can someone please confirm my actions?   I do not have an external HDD and am attempting repair in-place, with testdisk if possible. Searching for 'testdisk add partition' is returning few relevant results, e. g.,   I am trying to get specific advice about recovering the partition layout, or recreating it if it's corrupt beyond repair.
About two weeks ago I had a problem with my PC that my brother wrote a question about at .  I still haven't solved the problem, so my PC is unusable now.  Now I think that it would be simpler to re-install both Win7 &amp; Ubuntu than repair them, but there're some data on their partitions. I want to recover this data.  These partitions are not mountable for some reason. I don't know why.  sudo fdisk -l about the problematic partitions:     Device    Boot      Start         End      Blocks   Id  System /dev/sda1            2048     147912703    73955328   83 Linux /dev/sdb2            206848   174079999    86936576    7  HPFS/NTFS/exFAT   And in GParted:      And the error of the mount command:  Failed to mount '/dev/sdb2': Invalid argument The device '/dev/sdb2' doesn't seem to have a valid NTFS. Maybe the wrong device is used? Or the whole disk instead of a partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?   And the exact same message for /dev/sda1  How can I recover my data from those HDDs?  EDIT     I have tried to specify the type of the drive:  $ sudo mount -t ext4 /dev/sda1 /olddisk mount: wrong fs type, bad option, bad superblock on /dev/sda1,        missing codepage or helper program, or other error        In some cases useful info is found in syslog - try        dmesg | tail  or so $ sudo mount -t ntfs /dev/sdb2 /olddisk NTFS signature is missing. Failed to mount '/dev/sdb2': Invalid argument The device '/dev/sdb2' doesn't seem to have a valid NTFS. Maybe the wrong device is used? Or the whole disk instead of a partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?   EDIT     sudo ntfsfix /dev/sdb2 returns:  Mounting volume... NTFS signature is missing. FAILED Attempting to correct errors... NTFS signature is missing. FAILED Failed to startup volume: Invalid argument NTFS signature is missing. Trying the alternate boot sector Unrecoverable error Volume is corrupt. You should run chkdsk.
Why do we need multiple approvers for suggested edits? I already have the "Edit Questions And Answers" privilege. Yet, if I approve someone else's edit, I'm told that more votes will be required before the edit is accepted.  This seems a bit peculiar to me, since I could just copy the edited version and paste it myself. In the following setup, does method B run in a (new) transaction?  An EJB, having two methods, method A and method B  public class MyEJB implements SessionBean     public void methodA() {        doImportantStuff();        methodB();        doMoreImportantStuff();     }      public void methodB() {        doDatabaseThing();     } }   The EJB is container managed, with methodB in requires_new transaction, and method A in required transaction. thus:  &lt;container-transaction id="MethodTransaction_1178709616940"&gt;   &lt;method id="MethodElement_1178709616955"&gt;     &lt;ejb-name&gt;MyName&lt;/ejb-name&gt;     &lt;method-name&gt;*&lt;/method-name&gt;   &lt;trans-attribute&gt;Required&lt;/trans-attribute&gt;   &lt;/method&gt;   &lt;method id="MethodElement_1178709616971"&gt;     &lt;ejb-name&gt;MyName&lt;/ejb-name&gt;     &lt;method-name&gt;methodB&lt;/method-name&gt;   &lt;/method&gt;   &lt;trans-attribute&gt;RequiresNew&lt;/trans-attribute&gt; &lt;/container-transaction&gt;   Now let another EJB call methodA with an EJB method call. methodA now runs in an transaction. Will the subsequent call to methodB from methodA run in the same transaction, or does it run in a new transaction? (mind, it's the actual code here. There is no explicit ejb-call to method B) Deriving the conditional distributions of a multivariate normal distribution Let's fix some terminology first. A category $\mathcal{C}$ is preabelian if:  1) $Hom_{\mathcal{C}}(A,B)$ is an abelian group for every $A,B$ such that composition is biadditive,  2) $\mathcal{C}$ has a zero object,  3) $\mathcal{C}$ has binary products,  4) $\mathcal{C}$ has kernels and cokernels.  A category $\mathcal{C}$ is abelian if it is preabelian and satisfies:  5) every monomorphism is a kernel and every epimorphism is a cokernel.  Define the coimage of a map to be the cokernel of its kernel, and the image to be the kernel of its cokernel. We have the following commutative diagram:    where $\overline{f}$ is the only existing map (because of universality of kernel and cokernel).  I'm having trouble proving the following:     A preabelian category $\mathcal{C}$ is abelian iff $\overline{f}$ is an isomorphism.   The converse is easily shown, I'm having trouble proving $\Rightarrow$... Can Iranian-Canadians enter on arrival to the US? Why is printf better than echo? Having some trouble proving this:     If $f:\mathbb{R}\rightarrow \mathbb{R}$ is differentiable and $\lim_{x\to \infty } f^\prime(x)=0$ show: $\lim _{x\to \infty } (f(x+1)-f(x))=0$   Attempt: from $\int \lim _{x\rightarrow \infty } f^\prime(x) \mathrm{d}x=0$ we can say that $f^\prime(x)=const$ would we then have to show that  $\lim _{x\to \infty } (f(x+1))$ is also a constant? From there if we show that both are equal then the difference is zero. I am on the right track?  Thank you for the help. Prove inequality $\sqrt{\frac{2a}{b+a}} + \sqrt{\frac{2b}{c+b}} + \sqrt{\frac{2c}{a+c}} \leq 3$ Is the set of real matrices diagonalizable in $\mathcal M_n(C)$ dense in the set of all companion matrices? How can mixed content compromise an entire HTTPS session? Google Chrome is probably one of the stricter browsers out there in terms of highlighting SSL errors.  Most browsers will point out when you are viewing an HTTPS page which loads insecure images/Javascript, I understand how this is a security issue - an attacker could have modified the non-SSL content in a way which gives them access to the secure content, injected some javascript for example.  However once you have viewed an HTTPS page with mixed content, Google Chrome will continue showing you the mixed content warning (a red line through the 'https://') for as long as you stay browsing the same domain, even for subsequent pages which only include other HTTPS resources. Only once you navigate to another domain, or open a fresh tab does it tell you you're secure again.  What is the danger it's protecting you from here? How could mixed content on a previous page actually affect the security of subsequent secured pages? I understand that mixed content should be flagged up, but there must be a specific reason that Google is persisting this warning, other than "Well you still need to know about it" It seems the .NET Regex.Replace method automatically replaces all matching occurrences.  I could provide a MatchEvaluator delegate that returns the matched string after the first replacement, rendering no change, but that sounds very inefficient to me.  What is the most efficient way to stop after the first replacement? I have a list of requirements for a program, but I don't know what program meets these criteria. That's about general-purpose software, for example, not a programming IDE or statistical workbench, questions about which would certainly go to respective sites.  Is this question appropriate on Stack Overflow? Where should I ask about it? On Super User or elsewhere? Prove that $ S=\{0\}\cup\left(\bigcup_{n=0}^{\infty} \{\frac{1}{n}\}\right)$ is a compact set in $\mathbb{R}$. Prove that $ S=\{0\}\cup\left(\bigcup_{n=0}^{\infty} \{\frac{1}{n}\}\right)$ is a compact set in $\mathbb{R}$, but $\bigcup_{n=0}^{\infty} \{\frac{1}{n}\}$ is not a compact set.   (Can we use definition of compact set for this problem? ) Align cout format as table's columns I'm pretty sure this is a simple question in regards to formatting but here's what I want to accomplish:  I want to output data onto the screen using cout.  I want to output this in the form of a table format.  What I mean by this is the columns and rows should be properly aligned.  Example:  Test                 1 Test2                2 Iamlongverylongblah  2 Etc                  1   I am only concerned with the individual line so my line to output now (not working) is  cout &lt;&lt; var1 &lt;&lt; "\t\t" &lt;&lt; var2 &lt;&lt; endl;  Which gives me something like:  Test                 1 Test2                  2 Iamlongverylongblah         2 Etc                  1 How can we print line numbers to the log in java Why does an object with a glossy shader render in black? When I apply a glossy shader to the material of my text, the text becomes just black. Why?    I have lamp and everything, but the problem persists. The text is red before I add the glossy shader.  I'm using Cycles render.   Thanks! What’s the rule for adding “-er” vs. “-or” when forming an agent noun from a verb? What’s the rule to decide whether you add -er or whether you add -or when creating an agent noun from a verb?    Sometimes it’s -er:      read > reader hate > hater hit > hitter   But other times it’s -or:    meditate > meditator collect > collector How to draw arrows between parts of an equation to show the Math Distributive Property (Multiplication)? There is a part of my paper where I use the distributive property and it might not be clear to the reader to see the operation result (I'm using in proposional logic for a proof). The logic equation (part of) is: $$ (l_{1}) \vee \big( (p \vee q) \wedge (\neg p \vee q) \wedge (p \vee \neg q) \wedge (\neg p \vee \neg q)\big) $$ $$ (l_{1} \vee p \vee q) \wedge (l_{1} \vee \neg p \vee q) \wedge (l_{1} \vee p \vee \neg q) \wedge (l_{1} \vee \neg p \vee \neg q) $$  So I was wondering if there is a way to represent this operation like a 'shower' (see another example in pic ). Maybe there is some hidden magic mathmode command or pkg for this. At last we can also rely on tikz. What are the differences between consumer grade SSDs and the much more expensive enterprise SSDs? I am in need of a terabyte or so of storage space for Lucene indices on a testing server.  I'm having a hard time differentiating between disks like the  for about $450 vs  of dollars.  What concerns should I have regarding the 840 evo, and what should I be looking for?  This server will be used strictly for in-house testing purposes by our development team and will have to put up with periodic load testing. Should I use #define, enum or const?