Can we have 2 mount point under the same name but at different directory?

UNIX for Beginners Q & A
1

guys i would like to know can we have 2 mount point which is same name but on different directory?

2

Could you give us an exact example of what you want? To me it seems, as I see it right now, the answer is 'it is possible'. An example would really help.

# mountpoint is foo
/path/to/foo
 # completely different mountpoint
/another/path/to/foo
3

actually i getting this from etc/filesystems

/oranew:
           dev        =/dev/fslv04
           vfs         =jfs2
           log         =/dev/loglv02
           mount     =true
           option     =rw
           account   =false

/root/oranew:
           dev        =/dev/fslv04
           vfs         =jfs2
           log         =/dev/loglv02
           mount     =true
           option     =rw
           account   =false

and also i am not able to lsvg to the oranewvg..cant varyon and varyoff ..please assist.

thanks

4

This doesn't look great. I'm assuming that this is AIX. What version?

There is also confusion between what is a volume group, what is a logical volume and what is a filesystem, so I will attempt to summarise:-

  • Your server will have a number of physical volumes. These can be real disks or pseudo disks (often SAN LUNs or SAN Logical Units) which you would see as an hdisk device. If multipathing is involved on your server, they may be presented as a device that combines the various paths to the hdisks (one hdisk per device per path) so that you end up with a unit of space.
  • These physical volumes need to be formed into a Volume Group. There will be at least rootvg which should contain everything critical to getting the OS running, just enough for DR and nothing else. Other volume groups will be used for your software, applications and data.
  • Volume Groups are sliced into Logical Volumes so that you can sensibly segregate and size how you want to store the data. Because Volume Groups can contain multiple Physical Volumes, a Logical Volume can be bigger that a Physical Disk, indeed you can make a Logical Volume using all the Physical Disks in the Volume Group if you need to.
  • The Logical Volumes are usually formatted into Filesystems but can be left raw and used directly, e.g. given to a database.
  • Filesystems can be mounted explicitly on the command line or (more usually) added to /etc/filesystems automatically when you create them with mkfs or from within smit The Filesystem definition in /etc/filesystems includes the information, including the Mount Point that is used by default. If the value of mount is true, then the OS will attempt to mount the filesystem at the named mount point during the early part of the boot.

A filesystem cannot usually be mounted on more than one place at a time, however you can do this. Because of what you have, I would expect that the first entry in /etc/filesystems would be used and the second would get a failure because the logical volume is already in use.

So, to my question. What is your eventual goal? We might be better to set up a symbolic link so that any access to one 'mount point' actually affects the filesystem mounted at the other mount point. Another option would be use NFS, but that's more work.

Kind regards,
Robin