Questions dealing with Ubuntu's layout of files, permissions, and files that reside in special locations on disk.

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0
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2answers
320 views

ERROR : [cat: File does not exist] I can't open hadoop output file in 14.04

I have installed hadoop-1.0.3 in my system(14.04), followed this tutorial. And I successfully run an sample mapreduce program for wordcount as follows, hadoopuser@arul-PC:/usr/local/hadoop$ ...
7
votes
3answers
11k views

How can I convert my root partition from BTRFS to EXT4?

Is it possible to convert btrfs to ext4 without losing data? I'm experiencing a very low speed on read/write operations on btrfs.
3
votes
2answers
24 views

vmlinuz and initrd strange files appeared in “/” directory

I have recently noticed that four new files have appeared in my / directory: lrwxrwxrwx 1 root root 33 Apr 9 14:07 initrd.img -> boot/initrd.img-3.16.0-34-generic lrwxrwxrwx 1 root root ...
2
votes
1answer
20 views

How to get rid of disk icons in Unity launcher? [duplicate]

I have got here an installation of Unity and I am annoyed with the 3 disk icons in the Launcher right below the workspace switcher. Is there a way to prevent these icons from showing? Those 3 icons ...
4
votes
2answers
56 views
+50

How to run a script when a directory is changed by another user?

I know has been a bit of discussion about topics similar to this. But here is what I am basically trying to do. I have a watch directory called watched and whenever a file is added to that directory, ...
53
votes
6answers
7k views

How is 'rm -rf /' able to delete all files in the system?

I haven't tried this command on Ubuntu (for obvious reasons) so I am not sure if Ubuntu will allow its execution. But it's famous for deleting everything. Just out of curiosity, what happens when the ...
1
vote
2answers
51 views

What harm can a cold reboot cause into your computer? [on hold]

I was taking a look at the game DEFCON, and it froze my PC. Unfortunately, I only discovered the REISUB thing after a cold reboot. Now, what harm the cold reboot caused into my computer? Any type of ...
0
votes
0answers
24 views

How to allow only one program to read/write to a file at a time in Ubuntu?

Is there any way in the OS, to issue read/write lock on file? I mean, the file itself should not open, if a lock is issued! NOTE: Don't give me programming solutions.
0
votes
3answers
45 views

Unnoticingly I deleted a directory. Is there a way to recover it?

I found something over the internet here https://www.howtoforge.com/data_recovery_from_accidently_deleted_files_or_crashed_drives_in_ubuntu ...
64
votes
9answers
186k views

How do I view all available HDD's/partitions?

I found a 6 GB IDE HDD in my basement. I want to plug it in and see what might be on it. The drive seems to be recognized in BIOS. I can't find it in Ubuntu to view files, and Ubuntu is the only OS ...
13
votes
3answers
24k views

Can I disable full-disk encryption?

I recently installed Ubuntu 12.10 and it requires a passphrase to boot up (I installed it with an encrypted file system). Do I have to reinstall to change to a standard unencrypted file system?
0
votes
2answers
59 views

Use of “cp” command between root user's home and plain root

How do I use the "cp" command to copy files from root@pcname:/home/username # to root@pcname:~ # I have been able to use the mv command to move a file, but when I use cp, it tells me that the ...
26
votes
4answers
36k views

How do I use OverlayFS?

This answer and email message indicate that something called "OverlayFS" is available in Ubuntu 11.10 and will forcefully replace aufs in Ubuntu 12.04. How do I use it? Where is its documentation?
11
votes
1answer
162 views

Where are SMS and MMS stored?

I have BQ Aquaris E4.5 Ubuntu Edition phone and I'm not able to get MMS. If someone sends me a MMS, I just get empty message with no sender or anything. I can see those messages in message-app but ...
23
votes
2answers
1k views

Does the /dev/null file actually have a fixed size?

I have just found out that /dev/null is a file and not a directory. I'm just wondering if it has an actual file size.
0
votes
1answer
19 views

btrfs performance parallel access

I'm running a Raid5 (3x 500GB Sata2 HDD) based on btrfs 3.12 (Ubuntu 14.04 x64) and a VirutalBox VM uses this volume. As long as no other process accesses the volume, the VM runs fine. But recently I ...
0
votes
0answers
16 views

Linux, boot safe mode - repair broken packages not working?

Xubuntu 12.04 Application windows started to open only partly functional/broken? Some do not display fully, are not able to minimise, expand or close (missing these buttons) and are visually flat - ...
0
votes
0answers
9 views

How to hide btrfs devices in nautilus dynamicly

According to this question and answer: How to hide btrfs devices in nautilus? Is it possible to do this dynamically? Devices like /dev/sdc1 might not be the same on next boot, so a static ...
3
votes
2answers
4k views

Why does my root filesystem keep becoming read-only?

I've lately been having an issue with my root filesystem becoming readonly. It happens some amount of time after boot. I don't know exactly when it happens, as I don't usually notice it until ...
0
votes
0answers
33 views

Read only filesystem?

Whenever I try running apt-geti get this error: mike@mike-ubuntu:~$ sudo apt-get upgrade [sudo] password for mike: sudo:unable to open /var/lib/sudo/mike/1: No such file or directory W: Not using ...
12
votes
3answers
2k views

using locate on an encrypted partition

I selected /home/ to be encrypted when I was installing Ubuntu. Now, is it possible to make locate work with an encrypted partition like this?
0
votes
0answers
13 views

purpose of bamf-2.index [duplicate]

What is the purpose of /usr/share/applications/bamf-2.index ? I have noticed the applications it contains are installed in my computer. But I don't think it contains the complete list. Because the ...
2
votes
2answers
29 views

How to protect essential Windows files on NTFS partition from edit/deletion in Ubuntu?

So I made a mistake yesterday, accidentally deleting essential Windows files when working in Ubuntu (namely NTUSER.DAT). Just quickly my system set-up: I have Windows 7 (NTFS partition) and Ubuntu ...
57
votes
10answers
101k views

What is the equivalent to the Windows “Program Files” folder? (Where do things go when I install them?)

What is the Ubuntu equivalent to the Windows C:\Program Files folder? This is where Windows stores the system wide data for applications.
102
votes
6answers
33k views

How to understand the Ubuntu file system layout?

In Windows there’re perhaps only a couple of important folders (by important I mean important in my logical picture of the Windows file system) in the installation drive (in my case C:\). Namely ...
3
votes
1answer
100 views

How can I prune my BTRFS backups?

I have a BTRFS backup system where I take daily snapshots (btrfs subvolume snapshot) and serialize them into incremental change files based off the previous days backup (btrfs send -f backup.date ...
0
votes
1answer
15 views

Is O_NOATIME safe to ignore?

I am designing a filesystem to be implemented in FUSE. I have a question regarding what is allowed and best practice. There are 2 scenarios: User process calls open(..., O_NOATIME). Filesystem ...
6
votes
2answers
3k views

What is the easiest way to merge / and /home?

I have separate / and /home partitions, of which both use ext4 as their filesystem. How can I merge them, and what is the easiest way?
1
vote
2answers
30 views

Folder permissions changed [duplicate]

I have very specific questions regarding permissions. I have delved into the FilePermissions Wiki - https://help.ubuntu.com/community/FilePermissions Recently I installed an ecommerce open source ...
0
votes
1answer
30 views

Irremovable folder after wiping free space with bleach bit

I have a following problem. Yesterday I was using Bleach Bit as root to wipe free space. When I woke up Bleach Bit was not Responding and the terminal hangs on "suffix length = 235". So I force Bleach ...
5
votes
3answers
21k views

Gtk-WARNING : Calling Inhibit failed

I was trying to use gedit, when I came across the following problem: myPC@TM77:~$ sudo gedit /etc/pm/config.d/config (gedit:12512): IBUS-WARNING **: The owner of /home/myPC/.config/ibus/bus is not ...
0
votes
0answers
32 views

Ubuntu: Unable to mount SD card

I did go through other similar questions and realized that although the questions are the same but for the different reasons. Nothing so far I have tried based on online-help or suggestion helped me. ...
2
votes
0answers
22 views

What's up with the sudden appearance of .AppleDouble folders all over my filesystem?

Something I have never seen on my Ubuntu machine before now- .AppleDouble folders have appeared in many different folders all over my filesystem. It creeped me out- like someone on a Mac was looking ...
2
votes
1answer
23 views

Number of files shown via Properties and when copying are different?

I have looked at "Properties" of a folder to see the number of files and the folder's size. When I decided to copy the folder to my Desktop, number of files and the folder's size shown on the progress ...
0
votes
1answer
37 views

Which subdirectories of / should have compression disabled in btrfs root filesystem?

Imagine you set up your root filesystem to be btrfs with Ubuntu 14.10 defaults (one subvolume for / and one for /home) and you want to compress and deduplicate as much as possible. Which directories ...
0
votes
1answer
24 views

Dynamically set user groups for directories and files on a directory

I have made some vhosts which resides on my home folder, and i have given the group access to www-data user. This way the project (a web system) renders on the browser. This is a symfony based ...
5
votes
4answers
37k views

Damaged SD card (badly unmounted?) How to fix?

First Off I'm using Ubuntu 12.04 on a laptop with a built in card reader. I have a sandisk 8Gig micro sd card that came with my HTC Desire HD phone. Unfortunately I had mounted it to a windows ...
2
votes
1answer
14 views

Get back Documents folder? [duplicate]

I deleted my documents and downloads folder. How can I get them back. I don't want them to be like any other folder, I would like it to be like how it used to be where it shows on the side of the ...
2
votes
2answers
46 views

/opt folder missing in Ubuntu 14.04

I'm trying to install Eclipse "by the book" in /opt, but when trying to access /opt, it seems that /opt directory doesn't exist in Ubuntu 14.04: $ cd /opt/ bash: cd: /opt/: No such file or directory ...
0
votes
3answers
4k views

Get the access to the folder file system/root

I am using a live version of Xubuntu on USB for a extraordinary maintenance of my PC. I have to copy a single file inside the folder file system/root. Currently I can browse the complete folder file ...
0
votes
1answer
23 views

I want to resize my mount point partition of ubuntu 12.04 and install winndows 7 .HOw can I do that? [duplicate]

I want to resize the Ubuntu 12.04 partition and install Windows 7. How can I do that? Please refer to the screenshot of Gparted editor. I want to resize the dev/sda3 partition.
0
votes
0answers
21 views

Ubuntu hard reboot. Failed to power

I was told to do a hard reboot on my ubuntu 14.04.2 Ubuntu Desktop. Once i did it didn't turn completely back on. So i got prepared to run fsck, So i put in the recovery disk and rebooted my computer ...
1
vote
0answers
37 views

I can't access into my Ubuntu account 14.04

For disgrace I have asked advice in "chiedi Ubuntu" forum - the Italian version of ask Ubuntu - and for following their advice, I can't get anymore in my Ubuntu account due to internal errors of the ...
2
votes
2answers
5k views

Why can not change the file /proc/sys/net/ipv4/ip_forward?

$ sudo echo 1 >/proc/sys/net/ipv4/ip_forward bash: /proc/sys/net/ipv4/ip_forward: Permission denied then I try to get write privilege, also failed. $ sudo chmod a+wx ...
9
votes
3answers
4k views

How can I optimise ext4 for reliability?

As ext4 was introduced as more reliable than ext3 with block journals, is there any chance to suppose it 100% reliable? What if enabling block journaling on it, which is disabled by default? As ...
1
vote
1answer
479 views

Sanddisk drive write protected

My sanddisk usb write protected i tried ashokkrishna@ashokkrishna-Lenovo-B560:~$ sudo mount -o rw /dev/sdc1 /mnt mount: block device /dev/sdc1 is write-protected, mounting read-only # sudo mkfs -t ...
0
votes
1answer
44 views

Manual Partitioning During Installation: Understanding File System Types

I am wondering if anyone can help me understand the difference(s) between the different file system types: ie. swap, ext4, reiserfs, etc... I am working with the manual partitioning during ...
3
votes
1answer
4k views

How do you fix file permissions for root directory?

What is the best way to fix Ubuntu's Root file system permissions? I was changing file permissions on a whole bunch of files that needed to be removed, I had accidentally changed the permissions ...
7
votes
1answer
175 views

Where do deleted files go in Ubuntu?

I have a very simple question. Where do files go when you delete them? I know when I send files to "Trash", they go to "trash", but when I delete them, I do not know where they go.