I have a Centos 7 VM and I want to know what consumes the 126G on the  /dev/mapper/centos-root fs. I have 2 mount points and I unmounted them to make sure there's nothing reserving space under them and mounted them again .    I've also ran sudo lsof +aL1 but there was nothing reserving GBs  Is there more efficient way to know what consumes space ?
When I sum up the sizes of my files, I get one figure. If I run du, I get another figure. If I run du on all the files on my partition, it doesn't match what df claims is used. Why are there so many different figures for the total size of my files? Can't computers add?  Speaking of adding: when I add the “Used” and “Available” columns of df, I don't get the total figure. And that total figure is smaller than the size of my partition. And if I add up my partition sizes I don't get my disk size! What gives?
To tell about a guess about a case in the past, why use "would+have+past participle" instead of "must+have+past participle? I have seen this sentence in an article on bbc, which is about how people lived thousands of years ago. &quot;When this Neolithic home was built, it would have had a cosy roof of turf..&quot; When I read it, I got confused. Because the fact seems as a simple past situation or guessing/assumption about something in the past. it simply gives information about a past event, eg &quot;when I was a child, I had a blue toy car. I have been making a lot of research on whether or not this structure &quot;would+have+past participle&quot; could be used instead of the simple past or &quot;must+have+past participle&quot;, but I could not find any satisfying explanation. Almost all grammer contents cover this structure is used when we imagine the opposite of what actually happened in the past eg. &quot;referring to a missed opportunity&quot; (eg. &quot;if you had come to the party, you would have seen Tom.&quot;), But, in this case of this sentence, &quot;type 3 conditional&quot; is irrelevant. It is not an if sentence,  It simply gives information about how this house was like or was probably like when it was built long ago. Just like it would be If and old lady would want to tell about &quot;how she was like when she was a child years ago. she would simply say &quot;when I was a child, I had long curly hair.**. So &quot;when I was a child, I would have had long curly hair.&quot; would be wrong. So, my question is: 1-Does this structure &quot;would+have+past participle&quot; completely replace simple past sentences? or can be it be used instead of simple past? 2- If this structure was simply used because the author was not %100 sure about the fact as it was a long long time ago -so he wanted to make a guess or assumption, why did he not simply use &quot;must+have+past participle&quot; or &quot;it was likely that blah blah&quot; which must be used for guessing or assumptions about past happenings. Would it not have made more sense if it was like: &quot;When this Neolithic home was built, it must have had a cosy roof of turf. Often floats may land quite a bit later in the document than the point they are created, sometimes after a section break.  Is there a way to force a new section to start on a new page, after any unplaced floats? Discrepancy with lsof command when trying to get the count of open files per process If we pick randomly two points inside a circle centred at $O$ with radius $R$, and draw two circles centred at the two points with radius equal to the distance between them, what is the expected area of the intersection of the two cirlces that contain the origin $O$. I am on a MacBook Pro 13 running latest Sierra. I have an external Seagate solid state hard drive that was working and out of the blue stopped working. The only thing on it was my Adobe Lightroom images/videos. Not the LR DB files. I'm sure you have all heard this woe before, so I won't dwell on that. And yes, I back up to the cloud. AWS S3 specifically. Though I am traveling South East Asia for the last year, and staying in cheap hostels. So good internet is hard to come by sometimes. I can't back it up after every export. While most of it is backed up, there is some that is not.  Moving on. The symptoms seems to change every time I plug it in. The first sign was it ejected on it's own. I plugged it in again, and it wouldn't mount. Disk Utility recognized it, so did the command line diskutil list but it wouldn't mount. I rebooted and it worked for a second. Then I could only get to it from the command line. Then trying to frantically back up to my local what was not backed up to the cloud, it all failed. Basically just a cp -R [directory] [local-directory] command.  After some more frantic unplugging and re-plugging plus some command line manual mounts, I finally got it to where the Disk Utility would be able to run first aid on it. It failed. I don't recall the error. So I put it in a freezer. After a few hours I tried again. It is not any better. It still will not mount. Now Disk Utility sees it, but with no partition. I can't even give me information about how much space is used on it.  I have also tried it from a Windows machine. It did not mount. I have tried other cables. No success. As well as tried my other USB port. I also have another working external hard drive exactly like the one giving me issues. It works on all cables and USB ports.  I do have Docker running with a Ubuntu container, I'm trying to think of a way to see if I can try to get to the USB from there. I also have a USB that I have thought about running a live Ubuntu on there to see if I can mount and retrieve the data or fix the HDD that way. But if it will not mount, I doubt these will work.  Can anyone else think of any other tricks I can try myself to see if I can repair this or at least retrieve the data without paying for a service or software? If not, those suggestions are also welcome.  Update   I made the mistake in original post that it was a Solid State Drive. This is my mistake, it is actually a spinning disk hard drive. I bought them long ago and have been traveling with them for so long I just forgot. Question is updated to reflect this. Now diskutil list does not show it at all. The Disk Utility app also does not see it. Based on suggestion from @Allen I seeked out the USB to SATA cable. I did not quite find it, as my options are extremely limited where I am at. Though a local expat on a facebook group was able to help me with a empty 2.5 casing that I was able to extract the drive from original casing and put it in his blank case. It now mounts. Though it has the "click of death" sound to it. And data is not really reachable. While I can ls the directories and Adobe Lightroom does not have the exclamation mark when it can not reach the actual external files. Right clicking on the images and clicking on "Show in Finder" or any other variation of trying to get to the files through Finder or terminal, I have no success. It usually hangs and I get the spinning wheel. Since Adobe Lightroom imports these images into directories named by date, I am going to send the drive off to a data recovery service and ask to recover just unbacked up directories i.e. dates. Next time I will make harder efforts to backup and probably get an actual SSD.   I think this can be closed, due to my low reputation points I can not close this myself. Why are processes in Windows 8 32 bit? How is the notation $X\sim N(\mu,\sigma^2)$ read? Is it $X$ follows a normal distribution? Or $X$ is a normal distribution? Or perhaps $X$ is approximately normal..  What if there are several variables that follow (or whatever the words is) the same distribution? How is it written? Can you use Dispel Magic on the source of a spell (ie, the caster)? Bayes' Theorem Intuition I've been trying to develop an intuition based understanding of Bayes' theorem in terms of the prior, posterior, likelihood and marginal probability. For that I use the following equation: $$P(B|A) = \frac{P(A|B)P(B)}{P(A)}$$ where $A$ represents a hypothesis or belief and $B$ represents data or evidence. I've understood the concept of the posterior - it's a unifying entity that combines the prior belief and the likelihood of an event. What I don't understand is what does the likelihood signify? And why is the marginal probability in the denominator? After reviewing a couple of resources I came across this quote:     The likelihood is the weight of event $B$ given by the occurrence of $A$ ... $P(B|A)$ is the posterior probability of event $B$ , given that event $A$ has occurred.   The above 2 statements seem identical to me, just written in different ways. Can anyone please explain the difference between the two? Can't change mouse influence in proportional editing mode I press O and I see it change to Proportional Editing mode, but when I press G and mouse wheel down/up, or arrow keys down/up, it doesn't change the influence area.    And I am, I press G and then I tried to scroll to change influence, but it's not working.    Done this aswell and it's not working The problem statement is: for $a,b$ coprime, prove that there exists positive integers $x,y$ such that $ax-by=1$.  The question is form Arthur Egnels' problem solving text, and from the chapter on the pigeonhole principle.    My question: His proof begins by generating a list $a,\ldots,a(b-1)$, where he then points out that each element in this list(which proceeds sequentially) doesn't have remainder $0\pmod{b}$.  He then shows that we arrive at a contradiction if we assume that we also don't get remainder $1$ in this list $\bmod b$.  To show the contradiction in this last statement, he first states that we would have positive integers $p,q $ where $ 0&lt;p&lt;q&lt;b$ so that $pa\equiv qa \pmod{b}$.  He then goes on to point out that since we $a$ and $b$ are coprime, we then have that $b| q-p$.  I understand the last part here, but don't see why we get $pa\equiv qa \pmod{b}$.  Thanks in advance How to create a new object instance from a Type One may not always know the Type of an object at compile-time, but may need to create an instance of the Type.    How do you get a new object instance from a Type? Are Canon EOS and Nikon DSLR lenses interchangeable? Can we use the lenses from, say a Canon EOS 550D kit (Canon EF-S 18-55mm) with a Nikon DSLR D5000 for example) ? Also, is the reverse possible ?  I'm looking at interchangeability between recent DSLR lenses only, and not with older lenses. Also, for "average" lenses, and not ultra wide/ultra zoom.  The reason for this question is that I'm trying to decide between a Nikon D5000 and a Canon EOS 500D. I like the Nikon better, but Canon is more popular here amongst people I can interchange lenses with :) I have windows 7 in Arabic. Now I dowloaded QGIS 2.14.3-2 in French.  But when I installed it shows Arabic menu/tools...  How can I change the menu language to French? Batch update/delete EF5 A continuous mapping is determined by its values on a dense set Can anyone make me understand in simple language why the second condition for being an Euclidean domain is superfluous ?  Why $v(a)  \leq v(ab)$ is not needed?  How we can deduce from the first one? What's wrong with this derivation that $i\hbar = 0$? Least rank of a matrix Let $A$ be a $7\times 7$ matrix such that it has rank $3$ and $a$ be $7\times 1$ column vector.  Then least possible rank of $A+(a a^T)$ is? ($a^T$ is transpose of the vector)  Intuitively I think it's $2$ as $a a^T$ has rank $1$, and the most it could affect is one row of $A$. I'm looking for a word that means     someone (especially a boss) who is not pleased (with your work, attitude etc.) no matter how hard you try.