A filesystem is a way to organize and store computer files with their data.

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10
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557 views

Symlink to part of the file?

Is there possible to create file that is just a sub-sequence of bytes from another file, like a symlink, but referencing only part of the file?
6
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4answers
3k views

mount ramfs as user

My fstab entry: none /home/jreinhart/ramdisk ramfs defaults,user 0 0 The directory before mounting: drwxrwxr-x 2 jreinhart jreinhart 4096 Oct 17 11:31 ramdisk The directory after ...
38
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2answers
2k views

Why is '.' a hard link in Unix?

I've seen many explanations for why the link count for an empty directory in Unix based OSes is 2 instead of 1. They all say that it's because of the '.' directory, which every directory has pointing ...
2
votes
1answer
793 views

Running a command when a CD/DVD/BD inserted

This seems like a simple question to me, but after two nights of searching and tinkering, I haven't been able to find anything promising. I am running a headless Ubuntu server. I want to be able to ...
2
votes
3answers
342 views

What is the recommended filesystem to use when reaching sizes of 50TB?

My initial google searches say XFS or ReiserFS, but what does the community have to say about this? What are your experiences with 50TB sizes and up? Edit: After inquiring on IRC I think I would ...
0
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6answers
10k views

Script to check for read only filesystem

How can I check a bunch of systems to find any filesystem that are mounted read-only? Possibly via a script?
82
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6answers
25k views

Why hard links not allowed to directories in UNIX/Linux

I read in text books that UNIX/Linux doesn't allows hard links to directories but soft links do. Is it because, when we have cycles and if we create hardlinks, and after some time we delete the ...
3
votes
1answer
2k views

Ubuntu 11.04 and large external drives

I have a Hitachi USB external 3 terabyte drive attached to a Dell Precision T1500. When connected to the computer running Ubuntu 11.04 (2.6.38-11-generic #50-Ubuntu SMP Mon Sep 12 21:17:25 UTC 2011 ...
1
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2answers
333 views

Copying linux install from non-RAID/x86 to RAID/x86-64

I'm copying an Ubuntu Server install from an x86 machine with a single hard disk to a new machine with x64 and two identical disks. Two partitions will span the new disks: One small-ish RAID1 for ...
3
votes
1answer
937 views

Warnings about read-only filesystems while installing a solaris package

I have a solaris machine that I am trying to install Perl 5.12 as well as gcc and make to get CPAN working. I downloaded the packages from sun freeware, and was able to install gcc. When I tried to ...
10
votes
3answers
4k views

How can I determine the fs type of my current working directory?

I need a platform-independent and lightweight way of detecting the mount type of my CWD. Specifically, I need to determine if my CWD is in an SSHFS, NFS, CIFS, SMB, or local block store mount. I need ...
5
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2answers
2k views

/dev/sda2 has gone 49710 days without being checked, check forced

Why the shell show "/dev/sda2 has gone 49710 days without being checked, check forced." at centos start and then reboot? ...... /dev/sda2: Superblock last mount time is in the future. FIXED. ...
2
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2answers
1k views

A command to check file access permission for another user

I need to know how to check the effective file access permissions for a given user, but it takes long to do this manually starting from / up to the target file or directory, checking group, ...etc.
4
votes
1answer
4k views

Is the file table in the filesystem or in memory?

In the context of operating system control tables, does the term "file tables" refer to a data structure that is part of the filesystem, or that is in main memory (and in which case I assume it would ...
12
votes
5answers
531 views

Which application should I blame for compulsively creating a directory again and again?

There's an application on my system which keeps creating an empty ~/Desktop directory again and again. I can't stand capital letters in my home, nor I can stand this “desktop” thingy. So, as picky as ...
4
votes
1answer
115 views

What is the proper way of sharing the /usr subdirectory?

What parts of the /usr subdirectory are usually shared in common practice without introducing any system instabilities? My intent is to share share-able parts of the /usr subdirectory among VM's of ...
17
votes
2answers
7k views

How can I find the number of files on a filesystem?

I want to know how many files I have on my filesystem. I know I can do something like this: find / -type f | wc -l This seems highly inefficient. What I'd really like is to do is find the total ...
1
vote
1answer
765 views

Resize LV's in a LUKS encrypted VG - Ubuntu 11.04

I wanted to resize the FS on a machine but i ran into problems: Purpose: the LV of /home is too big, the LV of / is too small (they're on 1 VG.) - I need to put 10 GByte from /home to /!! Problem: ...
2
votes
2answers
612 views

Did `sudo init 6` cause my file system to be corrupted?

I was developing some code and had open qtcreator (software development IDE), gnome-terminal, and possibly firefox. I needed to restart to test something. So i restarted using sudo init 6. When my ...
2
votes
1answer
134 views

“Short read block” error trying to boot RHEL

I changed my network configurations from static IP to DHCP and removed the DNS entry, etc. Then I rebooted the computer, but am now unable to boot, I get an error message along the lines of "short ...
34
votes
5answers
7k views

Why do hard links exist?

I know what hard links are, but why would I use them? What is the utility of a hard link?
2
votes
3answers
2k views

How to determine what filesystem a directory exists on?

I have an NFS share which is shared across about two other machines. I recently realized that one of the servers isn't sharing the directory and is keeping files all for itself. Is there a way to see ...
10
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1answer
2k views

Is it possible to run a webdav fuse client with no root access?

I have seen examples showing how to use davfs2 under linux, but each has involved one of these things: Running mount as root Adding an entry to /etc/fstab Running mount.davfs setuid, which, alas, ...
7
votes
1answer
2k views

When is exFAT coming to Linux? [closed]

It seems that exFAT is to be the next standard filesystem for removable media. The problem is, it is designed by Microsoft and made proprietary. However, it is the standard FS for the upcoming SDXC ...
8
votes
2answers
3k views

recursively change file permission but not directories?

I was doing a mass recursive change of permissions of some files that I had migrated to a unix system. I changed them to ug+rw, but then I found that I could not traverse subdirectories. I looked at ...
2
votes
1answer
115 views

Is there any method to mount a block of memory as a filesystem in linux?

I have a question,in linux, is there any method to mount a block of memory as a filesystem? For example, in X86 architecture, when power on, I reserve a block of memory about 8 Mbytes, and then when ...
4
votes
2answers
3k views

Permission denied (even as root) on a mounted ISO image with Furius ISO Mount

I mounted a ISO image with Furius ISO Mount. I cd to the mounted directory and tried to copy a file with sudo cp file /dir but cp writes error message cp: cannot stat `file': Permission denied ...
9
votes
3answers
2k views

Why is sorting files by access time not working?

I tried to use command ls --time=atime it was working in one directory but wasn't working in another directory. I opened certain files in vim, evince and other applications but after the command file ...
5
votes
3answers
2k views

recursively copy only images and preserve path

I'm working on a website migration. I have a scrape of the site, with all the files and directory structure as you would see them in the URL. I want to pull all images, maintaining the directory ...
25
votes
1answer
3k views

What do the device files in /dev actually do?

(Not a duplicate of Understanding /dev and its subdirs and files) I was browsing around my filesystem and for the first time I took a second to analyze my /dev directory. I was surprised by the ...
2
votes
3answers
959 views

Safest HardDrive Format for Archiving/Media Storage Data?

What is the safest hard drive format (NTFS, HFS+, XFS, ZFS, ...) for archiving or/and storing media (data)? I'd prefer to have the data not corrupt and be relatively safe (From corruption, ...) and ...
3
votes
2answers
76 views

Text files with sections in common with a given file

I need to maintain a set of plain text files saved in a directory which all have a section taken from another file. An example follows: Files: /directory/textfile1 (every other file in the directory ...
2
votes
1answer
7k views

how to make read only filesystem writable on busybox?

I want to change some files on my router. Firstly i can change everything in /var, but i want to change /etc/fstab. when i try to change it, i get an error message that says filesystem is read only. ...
4
votes
1answer
974 views

What happens to partition labels after removing a partition?

What will happen to all the remaining partition labels if I remove a single partition? For example if I have a layout that looks like this: /dev/sda1 /dev/sda2 /dev/sda3 /dev/sda4 /dev/sda5 and if ...
3
votes
1answer
593 views

How race conditions affect reads and writes (that happen at the same time)

Let's say I open a file a for reading. What if an application, let's call it aWriter writes to this file in random intervals. Are there any possibilities of me receiving improper file contents if I ...
6
votes
3answers
5k views

How to resize a VirtualBox HDD image

I initially created a dynamically expanding VirtualBox image, and have tried to increase its hard drive space: VBoxManage modifyhd "VirtualBox VMs/JHBuild/JHBuild.vdi" --resize 16384 After that, I ...
4
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2answers
969 views

How to construct a read-only compressed modular filesystem

I am designing a Linux distro and was toying with the idea of creating pre-packaged compressed bits of the filesystem that are merged with a read-only file system, and from there stacked under a ...
5
votes
2answers
3k views

Using vim to view the contents of a directory file

As I understand, in Linux directories are mostly normal files w/ some special handling (e.g. 'rm' a file is ok; 'rm' a dir will complain w/o -r). When I execute the following bash commands: mkdir ...
4
votes
4answers
3k views

How to recover a file just deleted [duplicate]

I just deleted a file in Nautilus with Shift+Delete, which warned me that "If you delete an item, it will be permanently lost." I wonder if there is no way to recover the file? My OS is Ubuntu 10.10. ...
9
votes
4answers
5k views

How are directories implemented in Unix filesystems?

My question is how directories are implemented? I can believe a data structure like a variable e.g. table, array or similar. Since UNIX is Open Source I can look in the source what the program does ...
1
vote
1answer
258 views

did a “ sudo go-wrx” on / … oops, broken

OK, I was trying to set up ssh to work properly, and a website said it was really picky about permissions, and to use go-wrx on ~/.ssh, and that / and /home need to have at least go-w permissions. on ...
7
votes
3answers
2k views

Why do we need to specify partition type in fdisk and later again in mkfs?

I'm a little confused about fdisk and mkfs. So - here is typical USB flash drive partitioning and formatting: umount /dev/sdb fdisk fdisk /dev/sdb Command (m for help): d Selected partition 1 ...
15
votes
2answers
4k views

What are the advantages of Btrfs for end users?

Btrfs has begun to gain some momentum in replacing ext4 as the default filesystem of choice for a few distributions such as Fedora Core 16. It is experimentally available in a number of other ...
2
votes
1answer
67 views

Creating Directories: with Permissions

I need to create a directory that is RW to all users using chown. what arguments should I pass chown to get a file with those permissions? Or maybe there is an even better way to do it......
2
votes
1answer
676 views

How are NTFS drives handled by Linux? Nothing is in fstab yet it's automounted. Nothing in mtab yet it's currently mounted

I'm running Fedora 14 with the 2.6.35.13-92.fc14.i686 kernel and Gnome 2.32.0. I have a few NTFS drives that are mounted when I start up. However, there is no entry for them in fstab and nothing in ...
320
votes
3answers
108k views

What is the purpose of the lost+found folder in Linux and Unix?

There is a folder at the root of Linux and Unix operating systems called /lost+found/ What is it for? Under what circumstances would I interact with it? How would I interact with it?
2
votes
1answer
1k views

CLI filesystem benchmark for random read/write with specified block size

I'm in search of a filesystem benchmark utility. I basically want to run a test which should be able to do random reads/writes on a specified drive with a given block size. e.g. a 4K random write on a ...
4
votes
2answers
452 views

How to configure CONFIG_DEFAULT_RELATIME to disable relatime

Since linux 2.6.30, filesystems are mounted with "relatime" by default. In this discussion, Ingo Molnar says he has added the CONFIG_DEFAULT_RELATIME kernel option, which: makes 'norelatime' the ...
9
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1answer
2k views

When was `relatime` made the default?

What is the first Linux kernel release to set relatime as the default mount option?
3
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2answers
181 views

How to detect out-bound port from PID

I have several applications that run on random ports. How would I take the pid or the file location and find which port it is running on? Example of desired output: www-data/apache = 80 ...