CentOS - Jun 2009 - logical volume over NFS permissions problem

Hi all,
i've problem with mounting logical volumes over NFS. 

On NFS server, i have following logical volume
[root at nfs_server ~]# lvdisplay
  --- Logical volume ---
  LV Name                /dev/escience/vv_25
  VGnfs_servernfs_servernfs_servernfs_servernfs_server      escience
  LV UUID                iMhNq7-iC7L-VTDO-Xcwv-a6yv-sEAD-EZWASV
  LV Write Access        read/write
  LV Status              available
  # open                 0
  LV Size                5.00 GB
  Current LE             1280
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:2


This logical volume is mounted on NFS server, the group information is 
taken from LDAP server.
[root at nfs_server ~]# mount | grep vv_25
/dev/mapper/escience-vv_25 on /export/escience/vv_25 type ext3 (rw)
[root at nfs_server ~]# ls -ld /export/escience/vv_25
drwxrwx--- 3 root vv153 4096 Jun 24 16:04 /export/escience/vv_25


But when i mount /export/escience on the nfs client, i'm missing all the
permissions and ownership informations:
[root at client ~]# mount.nfs nfs_server:/export/escience/ /mnt/escience
[root at client ~]# ls -ld /mnt/escience/vv_25
drwxr-xr-x 2 root root 4096 2009-06-24 16:04 vv_25


The setting of NFS exports is following:
[root at nfs_server ~]# cat /etc/exports
/export/escience     client(rw,sync,no_root_squash)
[root at nfs_server ~]# exportfs -v
/export/escience    
client(rw,wdelay,no_root_squash,no_subtree_check,anonuid=65534,anongid=65534)


Server is running latest CentOS 5.3
[root at nfs_server ~]# cat /etc/redhat-release
CentOS release 5.3 (Final)
[root at nfs_server ~]# uname -a
Linux nfs_server 2.6.18-128.1.14.el5 #1 SMP Wed Jun 17 06:38:05 EDT 2009 x86_64
x86_64 x86_64 GNU/Linux

No denials from selinux, client's IP is completely opened on firewall. 

Is there some possibility to debug the NFS mount process? I don't see
nothing more then verbose mode in man, which doesn't provide much 
informations :( Or is it some configuration issue?


thanks for help,
  Tom?? Ruprich <ruprich at uikt.mendelu.cz>
  DCD IICT MUAF Brno <www.mendelu.cz, is.mendelu.cz>
  tomyk at jabber.cz

Hi,

2009/6/25 Tomas Ruprich <ruprich at
uikt.mendelu.cz>:
> i've problem with mounting logical volumes over NFS.
You are mounting /export/escience and you want to access
/export/escience/vv_25 which is another filesystem. NFS (v2 and v3)
does not work that way, if you export and mount /export/escience, you
will get only the files in that filesystem and not in filesystems
mounted below it. It does not traverse mount points.

To achieve what you want, you have to export and mount
/export/escience/vv_25 explicitely.

Or you can investigate NFSv4, which AFAIR works the way you are trying
to use, but it has many differences from NFSv3 and there is some
learning curve involved.

HTH,
Filipe