Discussion:
trace attached - Folders in NFS-share: permission denied, prob. not 16+ groups problem
Steffen Kolbe
2006-05-08 09:08:59 UTC
Permalink
Hi,

- a client has mounted some nfs shares
- in these shares are folders wich are owned by different groups
- rights of these folders are 2770
- getent group: user is member in these groups (on server and client via
ldap)

but access to these folders says "Permission denied"

- if I copy the folder to local disk this error does not occur and the
user has access

After a tip from Neil Brown I've reduced the 2 test users to 14 / 15
groups - same problem.

I've traced the folder access traffic on client and server with
ethereal. They are here:
http://vwitme011.vkw.tu-dresden.de/~kolbe/nfs/nfs-trace-client.ethereal
http://vwitme011.vkw.tu-dresden.de/~kolbe/nfs/nfs-trace-server.ethereal

Any help ist welcome

-----------------------------------------------------------
general question:
Is their a real solution to use ~50 groups with nfs? Because we've many
project groups some team leaders, many crossover memberships over some
departments and .......
How is this solved in bigger environments?
------------------------------------------------------------

NFS-Server: Debian amd64 with nfs-kernel-server 1.0.7-12
NFS-Client: Debian i386 with nfs-common 1.0.7-11

best regards
Steffen



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Peter Staubach
2006-05-08 17:42:17 UTC
Permalink
Post by Steffen Kolbe
-----------------------------------------------------------
Is their a real solution to use ~50 groups with nfs? Because we've
many project groups some team leaders, many crossover memberships over
some departments and .......
How is this solved in bigger environments?
------------------------------------------------------------
The two most common solutions are either to use ACLs or use a security
flavor such as Kerberos. The 16 group limit for AUTH_SYS is hard and
is an RPC limitation and not an NFS thing.

Unfortunately, ACLs are difficult to adminstrate and to manipulate for
ordinary users. You could consider writing some tools to help your users
check and manipulate the ACLs as required.

The most common solution is to deploy Kerberos. This eliminates the
16 group limit, but does incur the cost and complexity of deploying and
maintaining Kerberos.

The only other alternative that springs to mind is to rearchitect the
entire solution. This is not usually something that people consider
doing... :-)

Thanx...

ps


-------------------------------------------------------
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Get stuff done quickly with pre-integrated technology to make your job easier
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Steffen Kolbe
2006-05-08 19:36:58 UTC
Permalink
Thanks.

Perhaps something in background to the system I would install/use.
Perhaps it's better for tips, how could I resolve this problem.

Server:
2x Win2003R2 for user management and "windows things"
-AD (LDAP, Kerberos) with SFU-schema
-because "easy" to install and most "work-ready" after install
(I'm started over years with MS, the user DB was also old MS. I would
migrate most to Linux, but
I'm not ready with "learning" Linux. LDAP+Kerberos server on Linux
isn't easy to understand/
install/configure for a single person, so it's MS AD because it must
work and it's easyer for me)
2x Debian (active-passive cluster) for server works: file, mail, print,
......
-all files/luns/config files mounted from active node via FC-SAN
before starting services
-nss via LDAP/nss_ldap against the MS AD
-pam/password via pam_krb5 against the MS AD
-NFS-Server, ....

Clients, Debian:
-nss via LDAP/nss_ldap against the MS AD
-pam/password via pam_krb5 against the MS AD
... until here this works all fine...
-network directories via NFS against the debian cluster ....so the plan

I don't like ACLs, so NFS with more groups is the better and easyer way
for me and the users in my opinion. Isn't ?
Is their a faq/help or so available, how to configure nfs for kerberos
(without auth_sys)?

Thanks and best regards
Steffen
Post by Peter Staubach
Post by Steffen Kolbe
-----------------------------------------------------------
Is their a real solution to use ~50 groups with nfs? Because we've
many project groups some team leaders, many crossover memberships
over some departments and .......
How is this solved in bigger environments?
------------------------------------------------------------
The two most common solutions are either to use ACLs or use a security
flavor such as Kerberos. The 16 group limit for AUTH_SYS is hard and
is an RPC limitation and not an NFS thing.
Unfortunately, ACLs are difficult to adminstrate and to manipulate for
ordinary users. You could consider writing some tools to help your users
check and manipulate the ACLs as required.
The most common solution is to deploy Kerberos. This eliminates the
16 group limit, but does incur the cost and complexity of deploying and
maintaining Kerberos.
The only other alternative that springs to mind is to rearchitect the
entire solution. This is not usually something that people consider
doing... :-)
Thanx...
ps
-------------------------------------------------------
Using Tomcat but need to do more? Need to support web services, security?
Get stuff done quickly with pre-integrated technology to make your job easier
Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
_______________________________________________
NFS maillist - ***@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/nfs

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