chmod fails without error

WantLinuxHelp · 08-02-2010, 01:00 AM

I have an external USB hard drive (sdb1) mounted at /media/Iomega HDD.

When I try to do a chmod to a directory on this drive, chmod doesn't give me an error, but it doesn't change the privs - even when I'm root. Why is this?

Code:

	root@d-desktop:/media/Iomega HDD# ls -lart
	total 2176732
	drwx------ 1 dan     dan            456 2010-08-01 16:24 Unison
	root@d-desktop:/media/Iomega HDD# chmod -v a+rwx Unison
	mode of `Unison' changed to 0777 (rwxrwxrwx)
	root@d-desktop:/media/Iomega HDD# ls -larth
	total 2.1G
	drwx------ 1 dan     dan      456 2010-08-01 16:24 Unison
	root@d-desktop:/media/Iomega HDD# /usr/lib/klibc/bin/fstype /dev/sdb1
	FSTYPE=unknown
	FSSIZE=0
	root@d-desktop:/media/Iomega HDD

paulsm4 · 08-02-2010, 01:22 AM

Couldn't have anything to do with "FSTYPE=unknown", could it

?

foodown · 08-02-2010, 01:23 AM

If the filesystem type is NTFS, you may not be able to change the permissions without using a non-native driver for NTFS filesystems. That, or it may be mounted read-only. Can you write to the drive at all? What does the 'mount' command report?

Note that the type is showing as "UNKNOWN"

acid_kewpie · 08-02-2010, 01:24 AM

what is the filesystem of the device? It'd need to be a valid posix filesystem in order to hold the rights you want in the filesystem metadata. fstype there doesn't give one, but mount must do.

WantLinuxHelp · 08-02-2010, 10:33 AM

Quote:

Originally Posted by paulsm4

Couldn't have anything to do with "FSTYPE=unknown", could it

?

I don't know. That's why I checked and included it in the posting.

WantLinuxHelp · 08-02-2010, 10:35 AM

Thanks for the response.

Quote:

Originally Posted by foodown

If the filesystem type is NTFS, you may not be able to change the permissions without using a non-native driver for NTFS filesystems.

I saw that somewhere, which is why I tried the fstype command. Why does it say "unknown?" Remember, it is a USB device, so it was automounted. I don't know the file type. It was preconfigured. It might very well be NTFS (preconfigured for windows users).

Quote:

Originally Posted by foodown

That, or it may be mounted read-only. Can you write to the drive at all?

I can write to the drive.

Quote:

Originally Posted by foodown

What does the 'mount' command report?

Here's what it says

Code:

d@d-desktop:~$ mount
...
/dev/sdb1 on /media/Iomega HDD type fuseblk (rw,nosuid,nodev,allow_other,blksize=4096,default_permissions)
d@d-desktop:~$

I don't know what that means, though. Does it tell me anything useful?

Quote:

Originally Posted by foodown

Note that the type is showing as "UNKNOWN"

Yes, I know. That's why I included that. How do I find out what the file system type is???

WantLinuxHelp · 08-02-2010, 10:37 AM

Thanks for the response.

Quote:

Originally Posted by acid_kewpie

what is the filesystem of the device? It'd need to be a valid posix filesystem in order to hold the rights you want in the filesystem metadata. fstype there doesn't give one, but mount must do.

OK. I included the output from the "mount" command in the response I just posted above this one. I don't see where it tells me anything about the file system type.

WantLinuxHelp · 08-02-2010, 10:38 AM

Maybe I should just reformat the entire drive? If so, what should I use? ext4? It's a 1 Tera byte drive (999 Gb)

WantLinuxHelp · 08-02-2010, 10:50 AM

Quote:

Originally Posted by WantLinuxHelp

Maybe I should just reformat the entire drive? If so, what should I use? ext4? It's a 1 Tera byte drive (999 Gb)

It took me a few years of dual booting Windows/Linux to get to the point of where I'm completely off of Windows. I haven't booted Windows now for 6 months or maybe a year. However, just in case, I want the external drive to be able to be used by windows. If I reformat it, is there a filesystem type I could use that meets all these criteria:

Readable and writeable by both OS's (Linux Ubuntu 10.04 and Windows XP)
Allows chmod from Linux
Supports a 1Tb drive

WantLinuxHelp · 08-02-2010, 12:03 PM

It appears as though this problem has been around (at least in SUSE) since 2006:

http://www.linuxquestions.org/questi...-fails-410944/

tredegar · 08-02-2010, 01:32 PM

Quote:

1. Readable and writeable by both OS's (Linux Ubuntu 10.04 and Windows XP)
2. Allows chmod from Linux
3. Supports a 1Tb drive

1] = NTFS FAT32 or FAT16
2] = any linux filesystem
3] = ext2 ext3 ext4 reiser .....

Quote:

It appears as though this problem has been around (at least in SUSE) since 2006:
http://www.linuxquestions.org/questi...-fails-410944/

Please do not cross-post / double-post your Q: I am going around in a loop here

The problem is that you want linux's chmod to apply to a non-linux filesystem (NTFS). This isn't going to work: NTFS (AFAIK) has no concept of rwxrwxrwx.

I believe there is a recently released win program that will enable win to read ext3 partitions, but as I haven't used win in years, I don't use it and have have forgotten what it might be called. "You know who" is your friend

So, find the win utility, install it, then format the drive as ext3: chmod will work on it (from linux) but win is not likely to understand what that means, or even obey the restrictions that work correctly with linux.

So I think your requirements (1,2,3) are mutually exclusive. Sorry.

An alternative would be to format the drive as ext3/4 and then allow win to access it over your network by running samba on your linux box. This would be my preferred choice.

HTH.

WantLinuxHelp · 08-02-2010, 01:48 PM

Quote:

Originally Posted by WantLinuxHelp

How do I find out what the file system type is???

I found out how to determine this. Gparted says it is NTFS. It's strange, though. Gparted says it cannot read the drive nor can it find the mount point.

WantLinuxHelp · 08-02-2010, 01:56 PM

Quote:

Originally Posted by tredegar

Quote:

Originally Posted by WantLinuxHelp

Readable and writeable by both OS's (Linux Ubuntu 10.04 and Windows XP)
Allows chmod from Linux
Supports a 1Tb drive

= NTFS FAT32 or FAT16
= any linux filesystem
= ext2 ext3 ext4 reiser .....

Thanks, HTH, for this and the other information in this post.

Quote:

Originally Posted by tredegar

Please do not cross-post / double-post your Q: I am going around in a loop here

I didn't. The other question was written by someone else in 2006. I did post a link to this thread in the other thread stating that more information was here, since that one was never solved. Sorry if that was confusing.

WantLinuxHelp · 08-02-2010, 02:21 PM

Quote:

Originally Posted by tredegar

3] = ext2 ext3 ext4 reiser .....

I found that NTFS has a 16Eb partition size limit (that's appx 16,000 Tb). Ubuntu forums had that here:
http://ubuntuforums.org/archive/inde...t-1497666.html

business_kid · 08-03-2010, 09:12 AM

If you enter the drive in /etc/fstab, and enter your info

/dev/sda /mnt/hd auto noauto,user 1 2
/wandering
The user part allows users play with it. Writing NTFS is a black art, since windows is supposed to spot if you change anything and go crazy - that was the idea behind ntfs back in the days when M$ thought it was OK for an OS to do a BSOD. Now it's a distinct (and repeated) embarrassment that they try to minimize.
/returning to subject
Don't leave it ntfs; it's hassle writing it from linux. Use fat32 - no hassle for any OS