NFS – Network File System WeeSan Lee

Roadmap Introduction How to setup a NFS server? How to setup a NFS client? nfsstat Automatic Mounting Q&A

Introduction Created by Sun in 1985 Was original designed for diskless clients Version 2 is slow  Write operation is not complete until receiving ACK from the server Version 3 permits async writes  Faster Version 4  Supports strong security, ACLs, unicode filenames, replication and migration, etc

Introduction (cont) Uses RPC  Remote Procedure Call – a system-independent way for process communication over a network Could be UDP and TCP  Now, TCP is preferable

How to setup a NFS server? /etc/exports  $ cat /etc/exports /home /24(rw,async,root_squash) /home/ftp(noaccess) /import /24(ro) $ exportfs -a /etc/hosts.allow  $ cat /etc/hosts.allow portmap: / mountd: / Map root UID & GID to nobody

How to setup a NFS server? (cont) /etc/init.d/nfs {start|stop|restart|reload|status}  portmap  rpc.statd  nfsd  rpc.mountd  rpc.rquotad Turns NFS on over reboot  $ chkconfig nfs on

How to setup a NFS client? /etc/init.d/portmap start  portmap  rpc.statd Manual mount the NFS partitions  $ mount :/home /home  $ mount :/import /import Mount the NFS partitions at boot time  $ cat /etc/fstab :/home/homenfsdefaults :/import/importnfsdefaults 0 0  $ mount -a

How to setup a NFS client? (cont) Experiment defaults with  soft,timeo=5  hard,intr To umount a NFS partition  $ umount /home To show the NFS server's export list  $ showmount -e

nfsstat Displays stats. about NFS server and client For server  $ nfsstat -s For client  $ nfsstat -c

Automatic Mouting Mount filesystems on-demand Originally comes from Sun To start  $ /etc/init.d/autofs start Master map file (/etc/auto.master)  Associates each mount point with a indirect map  $ cat /etc/auto.master /misc/etc/auto.misc /net-host

Automatic Mouting (cont) To automount /home & /import  Add the following lines into /etc/auto.master /home/etc/auto.home /import/etc/auto.import  $ cat /etc/auto.home *-soft,timeo= :/home/&  $cat /etc/auto.import *-soft,timeo= :/import/&

Reference LAH  Ch 16: The Network File System