USB Harddisk - Problems on writing

[Pollux]

Hi Knoppix users,

I am new to this forum and though I tried to get an answer for my question by reading the existing threads. This was not very successful since the hints did not work for me.

I want to use an external harddisk connected to the laptop through an USB inteface. The disk was mounted correctly at startup and was readable. The existing file system on this disk is NTFS. Any attempt to write to this disk failed with the error message: file system is read only.

First of all I am using version Knoppix 3.2 from CD. May this be the promblem? Should I use a newer version?

The following things I have tried without success:

- Changing the access right by clicking on the desktop icon and enabling writing. All changes had been accepted but the result was still the same.

- Unmounting the device and changing the option 'ro' in the file fstab to 'rw' and mounting the drive again. Afterwards the disk could be read again but not be written.

Thanks for any help

Pollux

[Harry Kuhman]

......I want to use an external harddisk connected to the laptop through an USB inteface.............. The existing file system on this disk is NTFS. .... file system is read only. .

You should not try to write to an NTFS file system with Knoppix. Best fix is, if you have files on the disk that you want to keep, move them to another computer, at least temporarly. Repartition the USB hard drive. Get rid of the NTFS partition, with make a linux partition or (if you want to use it with windows also), make one or more FAT partitions (any of the various FAT patitions should be fine). Move any files you want back onto the drive.

Knoppix, by it's very nature will default to opening the partitions as read-only. That's a basic concept of the Live CD apparoch, first do no harm. But as long as the partition is not NTFS you should be able to mount it as read/write and everything will be fine.


First of all I am using version Knoppix 3.2 from CD. May this be the promblem? Should I use a newer version? .....

A newer version shouldn't hurt, but will not resolve this. Newer versions do not write to NTFS either. On some systems the newer versions have required cheat codes on booting while 3.2 did not.

[Pollux]

Hi Harry,

thanks for your hints. It would be the easiest way to use the drive with NTFS without changing anythink. The problem is that I am just recovering a crashed windows system and trying to backup the files which are still accessable. Due to the lack of another PC my resources to save the existing data on that drive and then reformat it are limited. I must look for some help here.

I had read in an advice for Knoppix 3.6 that this release should be able to write to NTFS partitions. Is this statement not generally true? What restrictions should I be aware of? The changing history of Knoppix does not give any clear statement.

In summary I will try to follow your advice and will get rid off the existing files and reformat that drive with another file system.

[Harry Kuhman]

.... Due to the lack of another PC my resources to save the existing data on that drive and then reformat it are limited. I must look for some help here....
One PC with NTFS only and no one else to talk to makes it harder. You might consider adding a hard drive with one of the FAT file systems on it. Alternately, if you have a CD writer on that system you could write the data to CD's. Here are the issues there: Unless you have at least 3/4 gig of memory on the computer and uset the option "toram", then the Knoppix CD that you're running from has to stay in the drive it booted from, so with Knoppix you would need 2 drives or enough memory to use the toram option. There are other ways though. I made a bootable CD with another Linux distro called "Damn Small Linux" on it in the first session and left the CD open for writing. I used Damn Small Linus (only 50 meg in size) to write a second session on the CD, and was able to use the remaining 650 megs to save files. The CD no longer will boot, but has the files on it.

I'm also told that DSL has a toram feature, so you should be able to use that in most systems to load all of DSL into ram, then you should be able to remove the CD, put in a blank, and write 700 megs of data. I haven't done this yet, so it's all theory, but I see no reason why it should not work.