Comments on: Formatting usb pen in Linux

By: Anonymous J Coward

Anonymous J Coward — Mon, 21 Mar 2011 09:08:16 +0000

This seems to have a high ranking on Google search, so let’s answer Jitu’s question.

The error means that the USB disk is mounted. When mounted, it cannot be formatted. To format it, first un-mount it. E.g.

#umount /dev/sda1

(oh, and do double check sda is your USB drive – not your internal hard drive before formatting :), e.g. by running ‘df’ )

By: Mark

Mark — Fri, 11 Jun 2010 11:48:07 +0000

Jitu. You did not say what GNU/Linux you are using, but I will tell you exactly what I do to format MY USB pens.
I have two hard drives and a DVD burner. Hard drive 1 is sda. Hard drive 2 is sdb.
Gparted does not show me the DVD burner since it can not format it. With my USB pen plugged in, Gparted lists it as sdc or sdc1(First and only partition).
I use these instructions for Ubuntu 8.04 and 10.04.

1/ Be connected to the internet.
2/ From a command line terminal do: sudo apt-get install gparted
Give root password.
3/ Plug in your USB pen.
4/ Run Gparted, giving your root password when asked.
5/ Click the drop down box in the upper right hand corner of Gparted’s window. Identify which “drive” is your USB pen. Mine is hdc1.
6/ From command line terminal or console window do : sudo umount /dev/sdc1
7/ You may have noticed a set of keys symbol after /dev/sdc1, in the line describing your USB pen in Gparted, which means it was mounted.
8/ In Gparted’s menu click Refresh Devices. The keys symbol is now gone.
9/ Click on the line describing your USB pen, in Gparted, to highlight it.
10/ Right click on the line, choose “Format to” and “fat32″.
11/ Click the green arrow to apply your choices.
12/ Close Gparted.
13/ Unplug your USB pen. Plug it back in. It should be mounted automatically and be ready to use.
14/ Remember to empty the “Trash” now and then after deleting lots of files from the USB pen so as to actually free up the space.
Works for me!

By: Mark Luxton

Mark Luxton — Fri, 11 Jun 2010 01:22:34 +0000

I had forgotten about the post I made here till just now getting an email from the last poster. The original “problem” I was having was that I needed to empty the trash. Then I had the actual space to copy my files. I had deleted several GB’s of data from my 8GB USB pen, then I tried to copy several more GB’s to the pen. Although it seemed that I had the space, it wasn’t actually free till emptying the trash.
FAT 32 seems to work best all around.
Using Gparted to do the formatting is easy.

Jitu. Perhaps you need to unmount /dev/sda1 before formatting from the command line? Also you may need to do this with root access. Mounted means that the drive is currently part of the Linux file system/operating system, and is “in use”.

Make sure you have selected the correct drive. /dev/sda1 is most likely your hard drives first partition, which you can not format while you are running your operating system from it. That is a good thing!

By: Jitu

Jitu — Thu, 10 Jun 2010 17:34:30 +0000

Hi, ALL

Can anybody help in Linux, I want to my usb format when I went through this command #mkfs.vfat /dev/sda1 . This is not working and I got error like.mkfs.vfat: /dev/sda1 contains a mounted file system. what is this mean?

Thanks

By: Frank

Frank — Sun, 08 Feb 2009 23:35:32 +0000

Hi guys, I have been pondering similar thoughts. It is my understanding that FAT16 in LBA mode is limited to a partition size of 2GB. Although, it has been reported that up to a 4GB partition is supported but is known to cause issues. Can anyone shine further light on the limitations of a FAT16 partition? References: Link #1 and Link 2

By: Richard Steven Hack

Richard Steven Hack — Mon, 13 Oct 2008 21:48:17 +0000

As for not being able to copy large number of files to a FAT16 root directy, I vaguely recall there is a limit to the number of files FAT16 supports in a root level directory. I think you can only a maximum of 512 files in a root directory because under the FAT16 system the root directory has a fixed size whereas subfolders do not.

By: Mark Luxton

Mark Luxton — Fri, 15 Aug 2008 15:58:24 +0000

I have been using Gparted to set up my USB pen.
I find it near impossible to make mistakes this way.
I had formatted it as FAT16 and it works going from Linux box to windows box and back. Eventually the pen would not allow me to add files even though there was over 3GB available. Could this be due to the deletion of files only removing the TOC and not the actual data?
I just reformatted as FAT32 to see if that works better. Files are copying now. Is there a preferred format? FAT 16 or 32 or Linux Ext2 or 3. I realize it must be FAT to go to a Windoze box(or NTFS if all you got is Windoze).
Note: At one point I could not get a large group of files to copy to the root of the pen drive but was able to do so into a folder on the drive???