Nfsv4 configuration
From Linux NFS
from CITI documentation.
Contents |
NFSv4 configuration
Base configuration
This section may be skipped on most recent distribution. If so, go here
You should have already built and installed the kernel and user utilities and setup krb5.
The following steps need only be done once. It maybe skipped most recent distribution.
Add the following lines to /etc/fstab to mount the rpc_pipefs and nfsd filesystems automatically:
rpc_pipefs /var/lib/nfs/rpc_pipefs rpc_pipefs defaults 0 0 nfsd /proc/fs/nfsd nfsd defaults 0 0
and create the mountpoint for rpc_pipefs, and mount both filesystems:
- mkdir /var/lib/nfs/rpc_pipefs
- mount rpc_pipefs
- mount nfsd
Modify the fstab line for filesystem you plan to export on the server to add the "acl" option to the mount options.
Create a directory to export on the server:
- mkdir /export
- chmod a+rwxt /export
The following steps need to be performed on every boot; this should really be done by init scripts. The necessary init scripts already exist in recent Fedora distributions. See also debian/nfs-common.init and debian/nfs-kernel-server.init in the patched nfs-utils tarball for example init scripts.
On your server, run rpc.mountd, rpc.svcgssd, rpc.idmapd, and rpc.nfsd:
rpc.mountd rpc.idmapd rpc.svcgssd -> this is obsolete as of nfs-utils version 1.0.8-1 rpc.nfsd 8
- Feb 2012: I've added some updates on this in the below
On the client, run rpc.gssd and rpc.idmapd:
rpc.gssd -m rpc.idmapd
Exporting directories
Export your server directory (in this case, to anyone, using any authentication flavor), by adding the following lines to /etc/exports
/export gss/krb5(rw,fsid=0,insecure,no_subtree_check) /export gss/krb5i(rw,fsid=0,insecure,no_subtree_check) /export gss/krb5p(rw,fsid=0,insecure,no_subtree_check)
and then running
exportfs -r
(Note that if your server is connected to the internet the first line will give everyone in the world read and write access to /export and (with a little work) to anything on the same disk partition as /export! See the exports man page for more information.)
To access this export from a client:
Create a mountpoint on your client:
mkdir /mnt/nfs4/
and mount the server:
mount -t nfs4 yourserver:/export /mnt/nfs4/
or, to mount with kerberos,
mount -t nfs4 -o sec=krb5 yourserver:/export /mnt/nfs4/
Play around with the mounted filesystem:
cd /mnt/nfs4/ echo "Hello World!" >FOO cat FOO getfacl FOO
etc.
To mount a filesystem using krb5, provide the "-osec=krb5" option to mount. To export a filesystem using krb5, export it to the special client named "gss/krb5". Replace "krb5" by "krb5i" or "krb5p" for integrity or for privacy, respectively. The -osec= options should also work for NFSv3 exports and mounts.
Exporting and mounting can be automated using /etc/fstab and /etc/exports; see the man pages fstab(5) and exports(5).
Technical note: NFSv4 no longer has a separate "mount" protocol. Instead of exporting a number of distinct exports, an NFSv4 client sees the NFSv4 server's exports as existing inside a single filesystem, called the nfsv4 "pseudofilesystem".
The linux implementation allows you to designate a real filesystem as the pseudofilesystem, identifying that export with the fsid=0 option; we no longer recommend this. Instead, on any recent linux distribution, just list exports in /etc/exports exactly as you would for NFSv2 or NFSv3.
RPC Processes
1. openSUSE after starting the nfs server
ps aux | grep rpc
root 1231 0.0 0.1 2356 764 ? Ss 08:20 0:00 /sbin/rpcbind
root 3737 0.0 0.0 0 0 ? S< 08:28 0:00 [rpciod]
root 5215 0.0 0.2 3684 1208 ? Ss 09:26 0:00 /usr/sbin/rpc.svcgssd
root 5223 0.0 0.0 2416 344 ? Ss 09:26 0:00 /usr/sbin/rpc.idmapd
root 5227 0.0 0.1 2976 748 ? Ss 09:26 0:00 /usr/sbin/rpc.mountd --no-nfs-version 2 --no-nfs-version 3 (note the lack of gssd)
2. On both openSUSE (after calling rpc.gssd) and Ubuntu with all the necessary processes for successfully exporting the directory with -o sec=krb5<flavour>
ps aux | grep rpc
root 1231 0.0 0.1 2356 764 ? Ss 08:20 0:00 /sbin/rpcbind
root 3737 0.0 0.0 0 0 ? S< 08:28 0:00 [rpciod]
root 5215 0.0 0.2 3684 1208 ? Ss 09:26 0:00 /usr/sbin/rpc.svcgssd
root 5223 0.0 0.0 2416 344 ? Ss 09:26 0:00 /usr/sbin/rpc.idmapd
root 5227 0.0 0.1 2976 748 ? Ss 09:26 0:00 /usr/sbin/rpc.mountd --no-nfs-version 2 --no-nfs-version 3
root 5294 0.0 0.0 3816 428 ? Ss 09:31 0:00 rpc.gssd
NFS Installation details
openSUSE
Packages: zypper in nfs-kernel-server nfs-client nfsidmap limal-nfs-server
Configuration (Or use the excellent Yast NFS-Server Module) /etc/sysconfig/nfs
USE_KERNEL_NFSD_NUMBER="4"
MOUNTD_PORT=""
NFS_SECURITY_GSS="yes"
NFS3_SERVER_SUPPORT="no"
NFS4_SUPPORT="yes"
SM_NOTIFY_OPTIONS=""
NFS_START_SERVICES="yes"
STATD_OPTIONS=""
NFSV4LEASETIME=""
RPC_PIPEFS_DIR=""
SVCGSSD_OPTIONS=""
NFSD_OPTIONS=""
Ubuntu
Packages:
apt-get install nfs-common nfs-kernel-server (you may also need to do a: modprobe nfs before starting the nfs server)
Configuration
/etc/default/nfs-common
NEED_STATD=
STATDOPTS=
NEED_IDMAPD=yes
NEED_GSSD=yes
/etc/default/nfs-kernel-server
RPCNFSDCOUNT=8
RPCNFSDPRIORITY=0
RPCMOUNTDOPTS=--manage-gids
NEED_SVCGSSD=yes
RPCSVCGSSDOPTS=
RPCNFSDOPTS=
Needed on both client and server on both openSUSE and Ubuntu
/etc/idmapd.conf
[General]
Verbosity = 0
Pipefs-Directory = /var/lib/nfs/rpc_pipefs
Domain = hh3.site //or whatever your domain is
[Mapping]
Nobody-User = nobody
Nobody-Group = nogroup
Debugging
Run rpc.idmapd -fvvv and rpc.gssd -fvvv in separate terminals. They will tell you in no uncertain terms when you've got it wrong. Please see this screenshot:
http://3.bp.blogspot.com/-PLpbJDP1vCQ/TygMlNU6k8I/AAAAAAAAAGE/lVXsw6iGrS0/s1600/krb5-ubuntu3.png
A Real Life Example
hh3.hh3.site is the nfs server and HH6$@HH3.SITE is the machine principal for the client. On the client, we issue a:
mount -t nfs4 hh3:/foo /bar -o sec=krb5
Here is the log on the KDC:
Kerberos: ENC-TS Pre-authentication succeeded -- HH6$@HH3.SITE using arcfour-hmac-md5
Kerberos: AS-REQ authtime: 2012-02-06T19:44:47 starttime: unset endtime: 2012-02-07T05:44:47 renew till: 2012-02-07T19:44:47
Kerberos: Client supported enctypes: aes256-cts-hmac-sha1-96, aes128-cts-hmac-sha1-96, des3-cbc- sha1, arcfour-hmac-md5, des-cbc-crc, des-cbc-md5, des-cbc-md4, using arcfour-hmac-md5/arcfour-hmac-md5
Kerberos: Requested flags: renewable-ok
Kerberos: TGS-REQ HH6$@HH3.SITE from ipv4:192.168.1.10:45421 for nfs/hh3.hh3.site@HH3.SITE [canonicalize, renewable]
Kerberos: TGS-REQ authtime: 2012-02-06T19:44:47 starttime: 2012-02-06T19:44:47 endtime: 2012-02-07T05:44:47 renew till: 20
The nfs server has identified itself, here are the keys in its keytab:
klist -ke /etc/krb5.keytab Keytab name: WRFILE:/etc/krb5.keytab
KVNO Principal
1 nfs/hh3.hh3.site@HH3.SITE (arcfour-hmac) 1 HH3$@hh3.site (arcfour-hmac)
Troubleshooting
http://wiki.linux-nfs.org/wiki/index.php?title=Troubleshooting
References
1. man rpc.gssd(8)
http://linux.die.net/man/8/rpc.gssd
2. A hands on practical using modest hardware. Includes screenshots. openSUSE specific.
http://linuxcostablanca.blogspot.com/p/samba-4.html
3. The same as (3) but with Ubuntu specific differences
http://linuxcostablanca.blogspot.com/2012/01/samba-4-ubuntu.html
4. The latest unofficial version of this wiki page. Any new findings, I'll post there.
http://linuxcostablanca.blogspot.com/2012/02/nfsv4-myths-and-legends.html
