NFSv4.r (or rnfs) is an extention to the standard NFSv4 protocol that supports
mutable replication with consistency guarantees. The extention includes kernel 
patches for linux-2.6.16-rc3 and user-level patches for CITI nfs-util-1.0.8-rc2 
package. The code is useable for experimental setup, but not stable yet for 
production use. If anyone is interested in getting involved with the project, 
I will be very happy to discuss details on how to work together. Of course, 
any comments and suggestions are always welcome.

I. Installation (assume as root)
1. Kernel build
	1.1 Download linux-2.6.16-rc3 kernel from http://www.kernel.org/
		wget http://www.kernel.org/pub/linux/kernel/v2.6/testing/linux-2.6.16-rc3.tar.gz 
		tar zxvf linux-2.6.16-rc3.tar.gz
	1.2 Download and apply CITI kernel patch and rnfs patch
		cd linux-2.6.16-rc3
		wget http://www.citi.umich.edu/u/jiaying/NFSv4.r/linux-2.6.16-rc3-patches/CITI_NFS4_ALL-1.diff.patch
		patch -p1 < CITI_NFS4_ALL-1.diff.patch
		wget http://www.citi.umich.edu/u/jiaying/NFSv4.r/linux-2.6.16-rc3-patches/rnfs-all.patch
		patch -p1 < rnfs-all.patch
	1.3 Build kernel
		make menuconfig; make; make install; make modules_install
2. User-level helper build
	2.1 Download and build the packages that nfs-utils-1.0.8-rc2 relies on
		wget http://monkey.org/~provos/libevent-1.0b.tar.gz
		tar zxvf libevent-1.0b.tar.gz
		cd libevent-1.0b; ./configure; make; make install
		wget http://www.citi.umich.edu/projects/nfsv4/linux/libnfsidmap/libnfsidmap-0.19.tar.gz
		tar zxvf libnfsidmap-0.19.tar.gz 
		cd libnfsidmap-0.19/; ./configure; make; make install
		wget http://www.citi.umich.edu/projects/nfsv4/linux/libgssapi/libgssapi-0.10.tar.gz
		tar libgssapi-0.10.tar.gz
		cd libgssapi-0.10/; ./configure; make; make install
		wget http://www.citi.umich.edu/projects/nfsv4/linux/librpcsecgss/librpcsecgss-0.14.tar.gz
		tar tar zxvf librpcsecgss-0.14.tar.gz
		cd librpcsecgss-0.14; ./configure; make; make install
	2.2 Download nfs-utils-1.0.8 (a package is provided here)
		wget http://www.citi.umich.edu/u/jiaying/NFSv4.r/nfs-utils-1.0.8-rc2.tar.gz	
		tar zxvf nfs-utils-1.0.8-rc2.tar.gz
	2.2 Download and apply CITI nfs-utils patch and rnfs patch
		cd nfs-utils-1.0.8-rc2
		wget http://www.citi.umich.edu/u/jiaying/NFSv4.r/nfs-utils-patches/CITI_NFS4_ALL-2.dif.patch
		patch -p1 < CITI_NFS4_ALL-2.dif.patch
		wget http://www.citi.umich.edu/u/jiaying/NFSv4.r/nfs-utils-patches/rnfs-util.patch
		patch -p1 < rnfs-util.patch
	2.3 Build nfs-utils
		./configure; make; make install

II. Running
	1. Setup replica lookup method. Currently, we support DNS, LDAP, File configuration, and Server Redirect.
		For example, to set up File configuration, create a file /etc/nfs-replica.conf:
			rnfs.test	server1:/test -fstype=nfs4,rw,proto=tcp,rsize=32768,wsize=32768,intr 
			rnfs.test	server2:/test2 -fstype=nfs4,rw,proto=tcp,rsize=32768,wsize=32768,intr 
		In the file, each line contains "lookup-key  server:/path  mount-options"
	2. Start nfsd on nfsv4 replication servers. Give a special option fs_loc with exportfs. 
	   Make sure the replicated directory is identical on replication servers (e.g., run rsync before starting nfsd)
		rpc.mountd &
		rpc.idmapd
		rpc.rnfsd &
		rpc.nfsd 8
		mount --bind /nfs4/test /export/test
		exportfs -ofsid=0,rw,insecure,no_subtree_check *:/export
		exportfs -orw,insecure,nohide,no_subtree_check,async,fs_loc="file://etc/nfs-replica.conf:/rnfs.test" *:/export/test
	3. Mount nfs on client and start using it
		mount -t nfs4 server1:/ /mnt/nfs4
		ls /mnt/nfs4/test			// this is the replicated directory	
	4. Use -l option with umount to un-mount all mount points
		umount -l /mnt/nfs4

Author: Jiaying Zhang <jiayingz@umich.edu>