AIX

Why we create the VG?, by default rootvg is created by system,

why we create new vg? if we have option to utilize ur disk to rootvg (extendvg)

hi
rootvg is only for operating system file systems and it will be installed in the hard disk present in the server.
non rootvg filesystems will be present in the external san storage as you may get requirements to increase or decrease the filesystem size.
mksysb rootvg backup is always important as it can help in situations like server crash.
non rootvg backup is normally done through tools like vertias netbackup or legato networker
hence it is always essential to have non rootvg's in the server

thanks to give me answer, if i created testvg in san disk so how can i switched to testvg?

What do you mean to "switch"? If you created testvg, you just create logial volumes (LV) and file systems (FS) on it and mount it to use them, for example. There is no "switching".

I do not fully understand your question but it seems you are thinking with a "Windows" mind. You do not switch to a VG, Logical Volumes are created on the VG and filesystems are mounted on the LV. To see if the VG is varyed on type the command

Code:

lsvg -o

which should show rootvg followed by testvg. If it does not then try

Code:

lsvg

this will show all VGs. If testvg is not listed here then there was a problem with the creation! To check the disks configured to the server type

Code:

lspv

and this will give a listing of all the disks in the system. You will also notice the name of the VG at the end of each disk listing line to which the disk belongs too. If a disk does not have a VGNAME at the end of the line then the disk has not been added to VG.

really ur answer is clearly understandable, now i know the use of second VG, i have one more question like, i have SAN disk (150G) now please give me the next steps (with size) to make it working

Thanks sir

That is impossible with the sparse information you have given me. Are you declaring this on an LPAR or VIO server? The reason I ask is the commands on a VIO server are far more powerful when looking at unconfigured disks! Please run the following commands and paste the results here:

Code:

lspv
lsvg
lsvg -o
prtconf | grep -i model