Automounter

• allows automatic and transparent mounting of directories
• makes it possible to have a single home directory for all your users
• instead of one on each machine they log into
• can setup redundant filesystems in case one server goes down
• access to many filesytems but only mounts them on demand
• not configured in /etc/fstab file!

• filesystems to be automounted must be exported on the server
• a map is required on each machine
• contains the list of filesystems to be mounted
• the portmapper must be running before starting the automounter daemon
• NIS can be used to push the automount maps to client machines

Package requirements

•  autofs or amd
• check to see if you have autofs installed on your RedHat systems

# rpm -qa | grep autofs
autofs-3.1.7-21

Amd is also an excellent rubust automount package, however, since we have autofs installed on our systems we will proceed using autofs.
 

• Check that your kernel supports autofs

# cat /proc/filesystems | grep autofs
nodev autofs
      ^^^^^^

Any filesystem you wish to automount must be exported by its local server

# cat /etc/exports
/home 192.168.1.0/24(rw)
/mnt/cdrom 192.168.1.0/24(ro)
/distro 192.168.1.0/24(ro)

• default map file read by the automounter
• has a list of all automounter map files

# cat /etc/auto.master
/nethome   auto.home --timeout 60
/prj    auto.prj  --timeout 60
/misc   auto.misc
/net -hosts -nosuid,soft

# cat /etc/auto.home
pattyo -rw,noquota ponto:/home/pattyo
joel -rw,noquota ponto:/home/joel
conner -rw,noquota ponto:/home/conner
dylan -rw,noquota ponto:/home/dylan

# cat /etc/auto.prj
doc       -rw,noquota ponto:/home/oreilly/Linux/Doc
teaching  -rw,noquota ponto:/home/patty/Teaching/MCC

Samba Example but not recommeded
# cat /etc/auto.misc
oaxaca  -fstype=smbfs,login=pattyo,passwd=xxxxx  ://oaxaca/teaching

# /etc/rc.d/init.d/autofs start
Starting automount:                [  OK  ]
 
• You can restart this daemon to reload your maps after adding new mount points

# ls /prj/doc
afs
amd
automounter
backups
bootfloppy
certification
chroot
clock
debian-inst
dhcp
disk-part

/etc/mtab

• automatically generated
• kernel uses it to tracks all mounted filesystems


# tail /etc/mtab

 
//oaxaca/TEACHING /mnt/teaching smbfs 0 0 0
automount(pid16329) /prj autofs rw,fd=5,pgrp=16329,minproto=2,maxproto=3 0 0
automount(pid16306) /nethome autofs rw,fd=5,pgrp=16306,minproto=2,maxproto=3 0 0


/var/log/messages or /var/log/syslog (depending on your syslog.conf )
 

• logging for automounter
# tail /var/log/syslog

Apr  4 18:45:15 ponto automount[16116]: expired /nethome/joel
Apr  4 18:45:57 ponto autofs: automount -USR2 succeeded
Apr  4 18:46:03 ponto autofs: automount startup succeeded
Apr  4 18:48:42 ponto automount[16354]: expired /prj/doc

• Nis maps are compiled on the NIS Master server and pushed to the slave servers
• Simply add the automount map files and master map file to the NIS Makefile
• located in /var/yp and build


vi /var/yp/Makefile

add the NIS maps to appropriate locations
 
make
    build the NIS database in /var/yp/<NIS Domain>
ls -lt /var/yp/example.com
total 400
-rw-------  1 root root  12554 Apr  4 19:13 auto.home
-rw-------  1 root root  12526 Apr  4 19:13 auto.master
-rw-------  1 root root  12531 Apr  4 19:13 auto.misc
-rw-------  1 root root  12508 Apr  4 19:13 auto.prj
-rw-------  1 root root  13074 Apr  4 19:13 mail.aliases
-rw-------  1 root root  12569 Apr  4 19:13 netgroup
-rw-------  1 root root  12522 Apr  4 19:13 netgroup.byhost
-rw-------  1 root root  12470 Apr  4 19:13 netgroup.byuser
-rw-------  1 root root  29201 Apr  4 19:13 protocols.byname

ypcat -k auto.home
dylan -rw,noquota ponto:/home/dylan
conner -rw,noquota ponto:/home/conner
pattyo -rw,noquota ponto:/home/pattyo
joel -rw,noquota ponto:/home/joel