[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Random chmod errors
From: |
Peter Kratzer |
Subject: |
Re: Random chmod errors |
Date: |
Thu, 9 Jun 2005 10:44:59 +0200 |
> Peter Kratzer wrote:
> > some of my users are encountering random errors with the chmod command.
The
> > errors are not exactly reproducible, so I cannot even narrow down the
> > circumstances of their occurrance.
>
> Problems like that can be disheartening and hard to track down. I saw
> James' question and your response that you were working on an NFS
> server. I am not familiar with "NAS filer". But if there is any
> ability to look at logs for errors there that would be good. This may
> very well be a problem in the NFS between the systems.
Hi Bob,
thanks for your advice.
With "NAS filer" I am talking about a StorageTek Network Attached Storage
device, connected to the Linux machines by NFS.
I have checked the log files without success.
We have also contacted the StorageTek support. They don't have a clue
either. They suggested a network trace on the storage device. The problem
there is the trace stopa a file size of 1 GB. And that's nothing for lots
of users using the same machines and often producing hundreds of gigabytes
of hardware simulation data. As long as I cannot predicably reproduce the
problem I am lost there.
> > What else do I know:
> > - Following message occurs: "chmod: changing permissions of
> > `filename' (requested: 0644, actual: 0444): Operation not permitted"
>
> Seeing "operation not permitted" indicates to me that the filesystem
> (NFS server in this case?) refused the operation. That is also the
> message you would get when trying to chown without the privilege.
That's right. But there are two differences to that case:
1. The error message would occur a second time trying the same command,
which it does not.
2. In my case the additional output in brackets is produced, which it does
not if I really do not have the privilege to access the file's permission.
> I have had enough problems with NFS in the past that now it is one of
> my "usual suspects" whether it is really the problem now or not.
I will focus on NFS.
> > - The message differs from attempting to chmod files owned by different
> > users in the following part: "(requested: 0644, actual: 0444)"
> > - I have tried to find this message part in brackets ("requested: 0644,
> > actual: 0444") in the chmod.c source, but without success
>
> This may have been introduced in a downstream patch to the GNU
> sources. You could look at the RH distro source and see.
>
> I would build a pristine copy of latest coreutils. I would run all of
> the make checks because maybe in the tests on your system it would
> turn up something. I would place a copy of the pristine newly
> compiled chmod in /usr/local/bin so that it would shadow the distro
> supplied version for your users. If the problem goes away and that is
> the only change then you know it is due to something in the code. You
> should even be able to double-blind test it if you desired.
> Unfortunately if the problem remains you don't know anything more.
This is very helpful information. I will continue as you suggested.
Since I will not be in the office until monday I can start with this
procedure not before next week.
Thanks for your support so far.
With best regards,
Peter
> STABLE
> ftp://ftp.gnu.org/gnu/coreutils/coreutils-5.2.1.tar.gz
> ftp://ftp.gnu.org/gnu/coreutils/coreutils-5.2.1.tar.bz2
>
> BETA
> ftp://alpha.gnu.org/gnu/coreutils/coreutils-5.3.0.tar.gz
> ftp://alpha.gnu.org/gnu/coreutils/coreutils-5.3.0.tar.bz2
>
> Bob