NFS problem driving me insane

[Wishartz]

I have an extreme problem with NFS which is driving me insane.

Please help

I have checked on google numerous times and cannot find out the solutions to the problem.

I have one machine using FC3 and the other using FC4 64 bit version. Sometimes NFS works sometimes it doesnt. The only problem is I cannot see the pattern, what is the cause of the fix.

When I boot my machines up, I can see the share but it only dipslays one direcotry deep in the share.

For example /home/admin but does not show me the contents of admin.

I am as close as I can be at knowing this is a one hundered percent right config as how could it work sometimes and sometimes not. Note: it never works when I first boot up the machines, I usually have to try to unmount and then mount and all sorts of craziness.

Has anybody come acorss this problem before. It is seeing the share, by using mount -l on the clinet machine I can see that it has mounted, but only gives me /admin/home.....where is the contents.

Please help me.

I am using the instructions as per http://brennan.id.au and I know they work because I have copied across files at some point. It's just what am i doing to make it work? Is this a bug with nfs?

[urzasrage]

What is the exact command your use to mount the NFS share?

[amessina]

are you using nfsv3 or nfsv4? what are the contents of the /etc/exports file on the server? are you using selinux? are you unsing a firewall at all between server/client? are you using automount?

knowing these things will help us figure out where the trouble is.

i can also help you in my own support forum at http://messinet.com

[Wishartz]

I'm using nfs4

selinux is disabled from installation

exports is as follows:


/NFS4exports 82.152.102.80/28(rw,insecure,sync,wdelay,no_subtree_check,no_roo t_squash,fsid=0)
/NFS4exports/home 82.152.102.80/28(rw,insecure,nohide,sync,wdelay,no_subtree_check ,no_root_squash)
/NFS4exports/usr 82.152.102.80/28(rw,insecure,nohide,sync,wdelay,no_subtree_check ,no_root_squash)

Yea Im using a cisco router which is a firewall as well. It doesnt indicate a problem in the access control list because soetimes it works, not from when the computer boots up , but when I stop the service and restart and do whatever it that I do that makes it work. I cannot pin down what im doing that makes it work. ASt the moment everything i do doesnt make it work. Doesnt display furhter the /home/admin but no contents

[amessina]

i wish i could say wonderful things about nfsv4, but i can't. i find specifically that the rpcidmapd (rpc.idmapd) service does not function well as it often maps real user named to the nobody user. i tried working with nfsv4 for about two months to try to get things to work. often, what i found was that a username was mapped to the nobody user, so, specifically in the home directory, the nobody user has no access to the files, so they become inaccessible. i also had the same problem as you: sometimes it worked; sometimes it didn't. are you using kerberos at all? how are you mapping users? are you using /etc/passwd files or are you using ldap for centralized user management? another thing to consider for nfsv4 is that the permissions of the directories you create for the exports (on the server) are very important.

try this tutorial:

http://www.vanemery.com/Linux/NFSv4/...no-rpcsec.html

i found that page helpful, but i was still not able to get reliability with nfsv4. note: nfsv3 worked no problem!
i did find that nfsv4 was subjectively faster, i.e. i noticed a speed difference.

another question: are you only having problems with the /home directories, or are you having similar problems with all of your nfsv4 mounts?

something to try: after you load up and mount the nfsv4 mounts, go to a mounted directory and do:

ls -al

at the command prompt (thats "ell" "s" "space" "-" "a" "ell" phonetically). if you see that the user/groups are nobody, then your idmapping is not working properly.

[Wishartz]

I am exporting two directories:

/home
/usr

With both directories, when I try to list the contents there is nothing contained in there, so I asume to be having problem with both shares.

If I do ls -la

I get the following

ls -la home
total 8
drwxr-xr-x 2 nfsnobody nfsnobody 4096 Sep 14 20:43 .
drwxr-xr-x 4 nfsnobody nfsnobody 4096 Sep 20 19:45 ..

If I do the following command grep nfs /etc/passwd

This is the output

rpcuser:x:29:29:RPC Service User:/var/lib/nfs:/sbin/nologin
nfsnobody:x:4294967294:4294967294:Anonymous NFS User:/var/lib/nfs:/sbin/nologin

This command

vi /etc/idmapd.conf

gives me on both machines, so they are both matching nfsnobody

[General]
Verbosity = 0
Pipefs-Directory = /var/lib/nfs/rpc_pipefs
Domain = example.com

[Mapping]
Nobody-User = nfsnobody
Nobody-Group = nfsnobody

[Translation]
Method = nsswitch

It looks like I might have to change to NFS3 because it looks like a bug. Any ideas?

[Wishartz]

I think you may have solved it amessina. I followed your link to the howto and there was a section that told me to change the permissions

chmod 1777 /home

I did that to the rest of the directories and used exportfs -v , export -rv on the server and it seems to work on the client machine.

Thanks a lot mate. I really appreciate the help.

[Wishartz]

I spoke to soon the problem is back.

[amessina]

you see, it will work sometimes and not others. i have a feeling that the problem is with the rpcidmapd daemon which is unreliably mapping names to user ids. when you get the real name, it wrks. when you get the nfsnobody name it doesn't. the results of the mapping should be in syslog. after you reboot, try (as a regular user) to load one of these directories and the do a :

tail /var/log/messages -n 30

that should be enough to contain the most recent name to id mappings. if you see that any user maps to the nfsnobody uid (may be the number), then you know it did not work that time.

believe me, i googled this to death and looked for answers. i found none at this point. nfsv4 is still considered "experimental" so it is changing frequently.

you can take a gander at another page i found helpful:

http://www.citi.umich.edu/projects/nfsv4/

this my give you some more insight or a place to post your bugs.

keep a note to let me know if you ever get it working reliably. i'm dying to know myself. good luck.