Neat trick: Changing the permissions of an underlying mount point
A colleague of mine showed me a neat little trick in Solaris (I would guess sol 10 but perhaps earlier versions too) that I'd not seen before and thought I'd share here in case it's new for someone else also.
As most of you know, Solaris has the annoying habit of producing error messages when non-root users try to perform operations on filesystems mounted on a directory with less than 0555 permissions.
The only fix for this that I knew of (after hassling the engineer that got it wrong in the first place) was to stop everything that was using the filesystem, unmount it, change the perms, then remount again - yuck.
But this alternate way my colleague showed me appears to work without having to touch the filesystem mounted on our broken directory at all (obviously you should test this someplace safe before trying it in the wild though!):
Create some new mount point someplace:
Loopback mount the underlying filesystem:
Fix the permissions on your mountpoint:
Unmount:
And you're done!
So, the file system "does not care", but chmod is doing some kind of check to prevent working directly on a mountpoint. Does this work for all filesystems? You see can why I ask - who would bother to code chmod to "care" otherwise. There must be a gotcha somewhere.
So, the file system "does not care", but chmod is doing some kind of check to prevent working directly on a mountpoint. Does this work for all filesystems? You see can why I ask - who would bother to code chmod to "care" otherwise. There must be a gotcha somewhere.
I suspect I am misunderstanding your question but in case I do have you right, the chmod isn't really caring or not caring - it's just working on what it sees, as the second mount of the same filesystem wouldn't have anything mounted on top of any mount points underneath it.
So that allows one to 'see' the directory that would normally be obscured by the root of the mounted FS.
How to create a new mount point with 600GB and add 350 GBexisting mount point
Best if there step that i can follow or execute before i mount or add diskspace IN AIX
Thanks (2 Replies)
Hi All,
I have an nfs share which I mounted to my linux machine as below.
df -k output
TSDapp-na-02:/vol/tsd_app_1/rn_jira
47185920 11663072 35522848 25% /opt/rn_jira
I have no entry for this in my /etc/fstab. I did it by the following way.
mount -t nfs... (2 Replies)
Deart All,
can any one help to do this,
i need to change mount point in AIX 6
/opt/OM should be /usr/lpp/OM, how do i do....
Please help me Urgent issue (2 Replies)
I have an assignment where I have to temporarily change the permissions on a mount point so that an ordinary user can't access it. Can anybody explain how to do this? I know that to change permissions you can use chmod. First I'm not sure which category "ordinary user" would fall under: owner,... (0 Replies)
is there any command to know the list of mount points in a server.i need only the mount point lists.i tried using df but it was not helpful.i am using Solaris (1 Reply)
Ok. Here it is. I limited access to my external hard disk's partition/volume on Mac os X simply by changing permissions in Get Info window. But now the hard disk icon has disappeard and wont mount. Have tried different kind of soft to mount, but no luck. Then there is the utility called Terminal,... (0 Replies)
Hi All
I Know it is a really basic and stupid question perhaps...But I am going bonkers..
I have following valid paths in my unix system:
1. /opt/cdedev/informatica/InfSrv/app/bin
2. /vikas/cdedev/app
Both refer to the same physical location. So if I created one file 'test' in first... (3 Replies)
hi people,
I'm trying to create a mount point, but am having no sucess at all, with the following:
mount -F ufs /dev/dsk/diskname /newdirectory
but i keep getting - mount-point /newdirectory doesn't exist.
What am i doing wrong/missing?
Thanks
Rc (1 Reply)