Java, permissions, & NTFS

[LughClyde]

I'm a little confused. I have all my data on a hard disk that is NTFS. Partly because it's a left over from Win7 and partly to be able to dual boot back into Win7. (Yeah, I use it for Sony Vegas Pro. There nothing like that in Linux yet.) Mostly that works very well with no problems. However, I have one program with a quirky problem.

CmapTools is a Java program for concept mapping - that I love. It runs just fine. I even saves files to the NTFS disk without problems. However, it won't export to the disk. It has the ability to export PDF, JPG, SVG, and several other formats. It thinks that the permissions are wrong. Well, everything on the NTFS drive shows owned by root. This doesn't seem to be a problem for anything but this program's export.

I'm just wondering if there is some special permission issues with Java and programs that run under it. Is anything special or different going on here?

Thanks,
Clyde

[mads]

It thinks that the permissions are wrong.

Yes, me too. Edit /etc/fstab. Your NTFS line should look similar to this:

UUID=02782D66782D59A5 /e-windows ntfs defaults 0 0

[LughClyde]

Thanks for the reply.

That line looks like this:

#Entry for /dev/sdb1 :
UUID=389C10599C10144A /media/Stuff ntfs-3g defaults,nosuid,nodev,locale=en_US.utf8 0 0

What parts should I delete?

Thanks,
Clyde

[mads]

nosuid,nodev. If you want to know what they are/do see here. Mine looks like this:

Code: Select all

UUID=9498234498232468				/d-windows      ntfs-3g defaults,nls=utf8	0       0

And something else. Check the ownership of the mount point "/media/Stuff", and If it is owned by root, change the ownership to your login name. Assuming your login name is clyde, do

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sudo chown -R clyde:clyde /media/Stuff
touch /media/Stuff/testing
ls -la /media/Stuff

altair4 correctly reminded me (please see next post) that "chown" or "chmod" has no affect on NTFS partitions. So, the above would only be correct if the drive had been formatted with ext2 or ext3 file system.

[altair4]

There's something I don't understand in all this.

UUID=389C10599C10144A /media/Stuff ntfs-3g defaults,nosuid,nodev,locale=en_US.utf8 0 0

That will produce a mount point at /media/Stuff which has ownership:group = root:root and permissions of 777 meaning everyone has read / write access. And apparently it works:

CmapTools is a Java program for concept mapping - that I love. It runs just fine. I even saves files to the NTFS disk without problems. However, it won't export to the disk.

Not having any idea what CmapTools is or what it does, I'm wondering if CmapTools is attempting to alter the permissions on the export. That's not going to work. Linux can't change the ownership or permissions on an NTFS partition without an explicit mount or in fstab. "chown" or "chmod" has no affect on NTFS. If you wanted to take ownership of the mount point for example you would have to alter the fstab entry to look like this:

UUID=389C10599C10144A /media/Stuff ntfs-3g defaults,uid=1000,nosuid,nodev,locale=en_US.utf8 0 0

Where uid=1000 would be you.

Can you export to something in your home folder or some other linux formatted partition and see what the resulting ownership / permissions are?

[mads]

Linux can't change the ownership or permissions on an NTFS partition without an explicit mount or in fstab. "chown" or "chmod" has no affect on NTFS.

Sorry, you are quite right. What I wrote in the last part of my previous post, would only have been correct if the drive was formatted with ext2 or ext3 file system.

[LughClyde]

Thank everyone.

Alas, it didn't work. I added "uid=1000" and for good measure "gid=100" so my wife can get to /media/Stuff too. The whole partition is now 777 for me and "users". OK, it partially worked. All the text based export formats will now export just fine into Stuff. However, JPG, PDF, SVG, and other more complex exports still won't work.

However, this tells me that it's a problem with CmapTools and not Julia. So, I'm going to call this one solved, as it is from the viewpoint of this forum.

Thanks,
Clyde


PS - My daughter is named "Julia". Alas, Julia doesn't use Julia, but her husband does.