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

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3
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1answer
106 views

md5sum change after mount?

I have a ext3 filesystem on a .img file. After mounting and unmounting it, I noticed that the md5sum is changed, even if no file inside was changed! md5sum myfilesystem.img XXXX myfilesystem.img ...
2
votes
2answers
563 views

cannot touch -m a writable file

Can someone explain why I get permission denied when running touch -m on this file even though it is group writable and I can write to the file fine. ~/test1-> id uid=1000(plyons) gid=1000(plyons) ...
3
votes
2answers
15k views

How to extract boot.img?

I am trying to see the content in a boot.img file from an Android image. I googled and got http://javigon.com/category/development-tools/ to extract system.img. But it doesn't work for boot.img. When ...
2
votes
1answer
390 views

Why do inode-based file systems NOT need reboot after updating library versions? [duplicate]

I am trying to understand what an inode is. However, this passage from Wikipedia puzzles me: Installation of new libraries is simple with inode filesystems. A running process can access a library ...
4
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3answers
209 views

How to prohibit from changing an owner of modifiable files?

I sometimes need to run a Qt Creator from root. After that, some config files of Qt Creator suddenly have a root as an owner. Therefore when running Qt Creator as user, I am getting nag warnings about ...
2
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2answers
760 views

dynamic file system with hooks

Is there anyway in linux (I don't care which distribution or flavor) to have a dynamic file system with read/write hooks? For example I would like to mount a dynamic file system at /dynamic and ...
1
vote
1answer
188 views

Can a overlay/union file system be used as makeshift deduplication?

Given a union file system (mhddfs, unionfs, aufs) would it save me anything if I overlaid a writable file system over one with a bunch of ISO files, say Ubuntu 10.04, and then use zsync to update the ...
4
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2answers
786 views

Is there any performance penalty to having multiple segments for one volume in LVM?

We have a big drive that we've split up using LVM. We allocated one segment to the root filesystem and several other segments to other filesystems. Then we wanted to add more space to the root ...
2
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2answers
149 views

Circumvent permissions of filesystem on an external drive

Suppose that I have only non-root access on a desktop Linux machine. I want to work with an external, pluggable storage device (hdd, flash drive or memory card) with an ext{2,3,4} file system. Since ...
0
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1answer
63 views

see actual partitions usage

I have recently learned that ext3 (or some other filesystems) reserve some space of a drive by default for previliged processes. One can change this by doing the following: # tune2fs -m 4 /dev/sdXY ...
1
vote
3answers
297 views

Can a mounted encrypted filesystem be safe from root?

I have access to a shared remote computer from which I would like to run some code I have written which uses an interpreter (not a compiled code). I would like to protect this source code from other ...
0
votes
1answer
151 views

What is Linux for OpenVMS DIRECTORY/NOHEADING/NOTRAILING?

OpenVMS DCL command DIRECTORY/NOHEADING displays just the full file name including path info in a single-column format without any of the normal headings for a directory listing. The /NOTRAILING ...
13
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2answers
448 views

How can I be sure that a directory or file is actually deleted?

I know that most files, when deleted, aren't actually removed from the disk, and can be recovered later. How can I ensure that a directory I had deleted will actually be removed from the disk? Are ...
1
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0answers
1k views

How to set up ZFS with ZIL and L2ARC SSD?

I have been considering bcache and flashcache. However my friend suggested me something called ZFS. In fact it says that formating disk with ZFS can actually do the exact same thing without kernel ...
3
votes
2answers
899 views

Storing thousands of files in one directory

I have a web-site that I'm checking for performance issues and bugs, and i came across a caching code that caches thousands of files into one single directory. I understand that this is not good and ...
24
votes
1answer
4k views

Purpose of /dev/zero?

I tried to cat /dev/zero, and it didn't seem to do anything. I googled /dev/zero, and it says it's basically a blank file with infinite size. Is cat printing an infinite number of non-existent ...
2
votes
1answer
2k views

Resize ext4 partition to create more inodes? [duplicate]

Possible Duplicate: How can I increase the number of inodes in an ext4 filesystem? An old headless no-X backup server I use has a small hard drive with three primary ext4 partitions: /, ...
5
votes
1answer
1k views

updating `/etc/resolv.conf` on a read only filesystem

I currently have a busybox based embedded linux system. The filesystem is a readonly mounted jffs2 filesystem. One problem I've run into is that /etc/resolv.conf can't be updated by DHCP. Is it ...
3
votes
1answer
54 views

Emulating a file

I have certain application that opens a file with given path (presumably with fopen or derivative), reads the file, possibly writes to it and closes it. I have no control over this application other ...
8
votes
3answers
25k views

Best way to mount remote folder

I have two RasberryPi running debian wheezy and I would like to mount a folder from computer A on computer B. What is the best (as in most efficient) way to do this? I can do it via SMB, but that is ...
4
votes
5answers
120 views

Tool to compare files on one disk with registry information on another?

Been a long time since I got very far under the hood in Unix so I'm probably not even using proper terminology when I say 'registry,' but here's the situation. I have a disk thats dying. Lots of i/o ...
16
votes
3answers
2k views

Securely delete files on btrfs filesystem

Sometimes, there's the need to delete a file in a filesystem, and make sure that the file is truly gone. A file that contains sensitive passwords, for example, should be throughly wiped from the disk. ...
20
votes
2answers
5k views

How do I remove a file with no permissions?

A hacker has dropped a file in my tmp dir that is causing issues. Nothing malicious except creating GB's of error_log entries because their script is failing. However, the file they are using to ...
6
votes
2answers
743 views

FHS differences between OS X, Linux and FreeBSD

I've read that there is a different behavior between FreeBSD and Linux with the /usr/local, in FBSD ports are installed there, in Linux not, can someone explain more on this? I'd like to know where ...
0
votes
2answers
378 views

Problem mounting my iRiver story HD on Ubuntu

I would like to connect my iRiver Story HD to my ubuntu 12.04 machine but as I connect it I get this error: Unable to mount Story HD Error mounting: mount: wrong fs type, bad option, bad ...
30
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3answers
3k views

Why are text files 4kB?

For some reason, when I make a text file on OS X, it's always at least 4kB, unless it's blank. Why is this? Could there be 4,000 bytes of metadata about 1 byte of plain text?
1
vote
1answer
249 views

What parts of the filesystem to tmpfs/squashfs/sparseimage for USB live system

I want to create a live system on a USB key / SDCard with Linux Mint 14 (KDE or Debian Edition) that stores data persistently. The USB key needs to have at least one fat32 partition. As storage for ...
0
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0answers
46 views

Move files replacing? [duplicate]

Possible Duplicate: ‘mv’ equivalent of drag and drop with replace? I'd like to take a folder /a/b/c, and copy all files in /a/b/x into /a/b/c, replacing all files in /a/b/c with the ones in ...
1
vote
1answer
189 views

Cannot execute files on another partition

On my system I have three partitions: one is shared between W7 and Linux Mint (NTFS), and the other two are OS-specific. In my home directory I have created a symbolic link to another directory on ...
3
votes
2answers
871 views

Location of inodes (ext)?

Say I want to observe how the flow from file name to cluster on hard disc goes. I get the inode number of I file (which is mapped in a directory data): 1863 autorun.inf So, now i know that i have ...
3
votes
1answer
593 views

What do GDIR, GREG, VDIR, VREG mean in lsof output

The lsof manpage says the following about the TYPE column. TYPE is the type of the node associated with the file - e.g., GDIR, GREG, VDIR, VREG, etc. Can someone please explain (or point ...
6
votes
3answers
1k views

What are the advantages of the Unix file system structure

If I install an application in Linux for example Debian/Gnu Linux, the files of the applications are copied to many different directories in the file system. Some scripts goes into /usr/share .. ...
0
votes
1answer
384 views

The relationship between execute permission on a directory and its inode structure

My question deals with the relationship between the read and execute bits on a directory. I'm going to give my assumptions, first, all according to my current knowledge, then ask my question in bold ...
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3answers
1k views

Read a directory to see the file to inode mapping

I'm just learning about filesystems and it is said that a directory is just an ordinary file which keeps a list of file-inode pairs. If I try to open the directory Downloads with any of the following ...
1
vote
1answer
383 views

Filesystem with 1Mb block?

I'd like to make a partition for keeping ISO images of nightly builds. Most of files will be bigger than 1Mb. Unfortunately ext2/ext3/ext4 supports only 4Kb blocks. # mkfs.ext4 -b 1048576 -L DISTR -m ...
5
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2answers
12k views

Create and format exFAT partition from Linux

Is it possible to create and format an exFAT partition from Linux?
2
votes
2answers
69 views

Download copy of file which updates on change

Sorry about the title, I didn't know how to write it - It's kind of confusing. Ok, I am using my Raspberry Pi (Debian) and I store code on this server in which people have access to. My problem at ...
3
votes
1answer
684 views

How can I set a directory maximum size?

Is there an easy way to cap the size of a directory? I don't think there is but just wanted to make sure. I would like to set max directory sizes for some user home dirs as well as some other dirs, ...
1
vote
1answer
91 views

How do I give global access to a file in a private folder?

For example, I want all the files in /home/trusktr/Downloads/ to remain hidden from other users, except for one. I tried chmod 777 /home/trusktr/Downloads/someFile.avi but someFile.avi is still ...
0
votes
4answers
2k views

Optimal Setup for Windows & Linux - Sharing and Partitioning

This question gets a little complicated so please bear with me. So we have a new custom designed desktop which we will be mostly a dedicated machine for scientific computations in FORTRAN and ...
1
vote
1answer
243 views

Will kjournald takes too much space?

I am changing my hard disk to ext3 because journalling got so much write my server crash. Well, now I use SSD. Journalling is no longer the issue. But SSD are small. Will journaling takes so much ...
1
vote
1answer
928 views

Identify text/ascii files in Linux/Solaris

I have a little project to build bash script that search in the OS ( Linux/Solaris ) the current IP address from files and replace them with other IP address. The problem is that IP address could be ...
1
vote
0answers
140 views

Directly convert Archbang live on a USB drive to one such with persistent file-system

I have installed Archbang 2012.12.03 from ISO image on my USB drive, now I have a USB drive with a live Linux installed on it but at end of every session and rebooting system I faced with a fresh ...
5
votes
1answer
3k views

EXT4 FS needs journal recovery. What does this mean?

$ sudo file -s /dev/sdb1 /dev/sdb1: Linux rev 1.0 ext4 filesystem data (needs journal recovery) (extents) (large files) (huge files) What does "needs journal recovery" mean? Do I need to do ...
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0answers
123 views

Creating a Virtual filesystem to boot linux

I am trying to boot the linux kernel (bzImage) in QEMU but have had issues. After asking on U&L I found out that my problem was that I was booting the kernel without a filesystem to boot from. So ...
2
votes
1answer
903 views

How to find the type of an img file so it can be mounted

I have a .img file and I want to see what's inside of it. I tried mounting it, but I don't know what filesystem type it is. Is there a way to detect what it is so I can mount it? I'm using Ubuntu. ...
3
votes
1answer
396 views

Virtual file made out of smaller ones (for mac-like sparse bundle solution)

I'd like to recreate a feature of Mac OS X called sparse bundles (disk images made out of smaller files, making them easy to backup after a small change). For that I'm looking for a way to ...
4
votes
3answers
867 views

How do I point certain directory to /dev/null?

I am running CentOS with cPanel, which creates a custom log directory and writes the logs there. The result is that the IO for the hard disk goes sky high. If I do lsof I got: hostsite.com httpd ...
4
votes
1answer
146 views

How can I get a total for space used by a group of subdirectories

My file system is set up like: /ftp/data/ProductGroup*/ProductType*/Year*/Day*/ActualProductFile* ("*"denotes directory names that change) I'd like to find out how much space is being used for ...
18
votes
3answers
8k views

File system compatible with all OSes?

I use Linux and Mac OS X on a regular basis, and sometimes I have to use Windows. I need to use a flash drive on all three, and I need a filesystem that will work well on all of them. None of the ...