Linux - How do i know the block map of the given file and/or the free space map of the partition.

Posted by Inso Reiges on Stack Overflow See other posts from Stack Overflow or by Inso Reiges
Published on 2010-05-24T05:00:42Z Indexed on 2010/05/24 5:11 UTC
Read the original article Hit count: 253

Filed under:

linux

|

filesystems

Hello,

I am on Linux and need to know either of the two things:

1) If i have a regular file on some file system on a partition under Linux is there a way to know the set of the physical blocks that this file occupies on the drive from user space? Or at least the set of the file system's clusters?

2) Is there a way to get the same information about the whole free space of the given file system?

In both cases i understand that if there is any possible way to extract this info it will probably be totally unsafe and racy (anything could happen to these set of blocks between the time i see them and act on them somehow). I also really don't want an implementation that will have to know a lot about every filesystem.

© Stack Overflow or respective owner

Related posts about linux

apt-get install and update fail

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I've got a problem with apt-get update and apt-get install ... commands . every time update or installing fails and errors are : Get:1 http://dl.google.com stable Release.gpg [198B] Ign http://dl.google.com/linux/chrome/deb/ stable/main Translation-en_US Get:2 http://dl… >>> More
kernel module compiling error

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
sh@ubuntu:/home/ccpp/helloworld$ make gcc-4.6 -O2 -DMODULE -D_KERNEL_ -W -Wall -Wstrict-prototypes -Wmissing-prototypes -isystem /lib/modules/`uname -r`/build/include -c -o hello-1.o hello-1.c hello-1.c:4:0: warning: "MODULE" redefined [enabled by default] <command-line>:0:0: note: this is… >>> More
Build-Essentials installation failing

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I am having trouble accessing the several critical header files that show to be a part of the build process. The "Ubuntu Software Center" shows "Build Essentials" as installed: Next I did the following two commands, which did not improve the problem: ~$ sudo apt-get install build-essential [sudo]… >>> More
Updating Debian kernel

as seen on Super User - Search for 'Super User'
I'm trying to update my Debian machine to 2.6.32-46 (which is the new stable). However, after doing apt-get update my apt-cache search linux-image shows me: linux-headers-2.6.32-5-486 - Header files for Linux 2.6.32-5-486 linux-headers-2.6.32-5-686-bigmem - Header files for Linux 2.6.32-5-686-bigmem linux-headers-2… >>> More
Serial connection over a single USB cable (Windows to linux, or linux to linux)

as seen on Server Fault - Search for 'Server Fault'
I'm helping out with a project for an embedded device that only has USB and no serial. This device is running Linux. These days, when we need to connect to a serial port on a device we typically use a USB to serial adapter (on something like a phone system or a load balancing device, etc). I would… >>> More

Related posts about filesystems

Question regarding filesystems true or false?

as seen on Super User - Search for 'Super User'
Hello all, though I'm familiar with stackoverflow , and loving it , i've actually got a couple of questions myself about something other then programming. Here are my question Is it true that in FAT filesystems the maximum number of files per filesystem equals the number of entries in the FAT table… >>> More
Filesystems for webserver with SATA and Solid State disk,

as seen on Server Fault - Search for 'Server Fault'
We have just ordered a new webserver with 120 Gb solid state disk and a SATA disk. I am trying to plan ahead what sort of filesystem to use. This system will be running Linux, Apache/Tomcat to host java services. The main service is a system where people can upload reasonably large files (in the… >>> More
To see virtual filesystems in Ubuntu

as seen on Super User - Search for 'Super User'
How can you see the virtual filesystems at root? They should be /proc and /dev. >>> More
How do filesystems handle concurrent read/write?

as seen on Stack Overflow - Search for 'Stack Overflow'
User A asks the system to read file foo and at the same time user B wants to save his or her data onto the same file. How is this situation handled on the filesystem level? >>> More
Strange ZFS hidden filesystem problem

as seen on Server Fault - Search for 'Server Fault'
Half of my ZFS filesystems are hidden in ZFS-fuse. Here's my story: So, I love ZFS. I used it for about six months on FreeBSD, but due to it crashing the kernel during heavy inter-filesystem IO load, I tried switching to Solaris 5.10. That was good, but when I attempted to do an import of my Version… >>> More