SUMMARY : tcsh shell caching directories

From: Stephen Johnston (
Date: Wed Aug 25 1999 - 00:32:15 CDT

Hi All

Original question below.

Summary of answers;

Most shells cache top level directories because they do a getcwd when
they start.
They will also scan the path, manpath etc
Quota checking is done on mounted filesystems
Other code will scan top level as they do a getcwd

These activities (not sure about the quota thing) stat up the filesystem
until . = .. then they know they're in root. Other code will do this as
well, quite a lot.


Don't mount nfs filesystems form directly under root
Avoid having unecessary nfs mounted filesytems in your PATH and MANPATH

Thanks to all who responded.

Hope this helps those 'me too' responses. Sorry for the delay in
summarising I was on hols.



> From Fri Aug 13 08:20:01 1999
> From: Stephen Johnston <>
> Organization: ESO
> X-Mailer: Mozilla 4.6 [en] (X11; I; Linux 2.2.5-22 i686)
> X-Accept-Language: en
> Mime-Version: 1.0
> To: sun-managers <>
> Subject: tcsh shell caching directories
> Content-Transfer-Encoding: 7bit
> Hi All
> I have been told the tcsh caches top-level dirs so 'ls' and other
> commands are quicker and the shell only has to check it's up to date
> rather than get the whole information again.
> I have found that if an NFS server is down it means people cannot log
> into a machine which mounted this NFS filesystem - even if they do not
> access it at all, ever :(
> Is this true and what can I do about it?
> Stpehen.

Stephen Johnston                                  Phone: +49 89 32006760
UNIX Administrator                                Fax  : +49 89 32006380
European Southern Observatory
Karl-Schwarzschild-Strasse 2
D-85748 Garching bei Muenchen

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