Basic format: mount -t <filesystem type> old_dir new_dir
1> Mounting a directory to another directory to let them access the same content
mount --bind old_dir<directory has content> new_dir<directory designed to access the content>
2> Mounting a device <like CDROM> with no -t parameter, it will let the OS to guess
mount /dev/cdrom /cd
3> NFS
- /etc/exports specifies the access control of the mounting directory.
/home vale(rw) vstout(rw) vlight(rw)
/usr/X11R6 vale(ro) vstout(ro) vlight(ro)
/usr/TeX vale(ro) vstout(ro) vlight(ro)
/ vale(rw,no_root_squash)
/home/ftp (ro)
/var/myApp 172.16.95.17/255.255.255.255(rw,no_root_squash)
Each line defines a directory and the hosts allowed to mount it. Wildcard is allowed (* ?).
Range of ip address / network mask can be used to specify the host.
If no host is give, any host matches and is allowed to mount the directory.
[root@localhost ~]# cat /etc/fstab
/dev/VolGroup00/LogVol00 / ext3 defaults 1 1
/dev/VolGroup00/LogVol01 /data ext3 defaults 1 2
LABEL=/boot1 /boot ext3 defaults 1 2
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
LABEL=SWAP-sda6 swap swap defaults 0 0
172.16.95.93:/var/myApp /logserver-1/var/myApp nfs hard,intr 0 0
4> fstab and mtab
[root@localhost ~]# cat /etc/fstab
/dev/VolGroup00/LogVol00 / ext3 defaults 1 1
LABEL=/boot /boot ext3 defaults 1 2
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
/dev/VolGroup00/LogVol01 swap swap defaults 0 0
/var/myApp /localserver-1/var/myApp none rw,bind 0 0
There are 3 ways of using fstab.
1> mount -a will cause all the filesystem listed on fstab to be mounted, except those noted as noauto. Adding the -F will make mount fork. Usually it is used by boot scripts.
2> To mount or umount the filesystem mentioned on the fstab, it is sufficed to give only the device or the mount point.
e.g In fstab, /tmp/a /tmp/b none rw,bind 0 0
mount /tmp/a or mount /tmp/b will suffice.
3> Normally, only the superuser can mount file systems. However, when fstab contains the user option on a line, anybody can mount the corresponding system.
