newbie aix lvm question

[nyck]

Hello,

I have an aix5.2 server that i need to create some file systems on for an oracle install. I have been having a look through wsm and it looks pretty straight forward. I have created a volume group for this on a spare disk and my question is do i create a logical volume for this or just create a file system. I have created a logical volume but am unable to do anything with this. So i created a file system and hey presto all was fine. So can someone explain why i would create a logical volume?

Cheers

Nick

 

[p5wizard]

A logical volume is where a filesystem resides on. Compare it in "winspeak" to a newly created disk partition, which is useless until you format it and then you have a drive letter for it.

You can create an LV manually and create a FS on that LV.

You can create a FS in a volume group without bothering to create an LV first, the system will then create an LV for you.


Type

lsvg -l <your_vg_name_here>

You'll see the FSs and their LVs, and probably you'll see an empty LV - the one you created first, unless you have built a FS on top of that first LV too.

HTH,

p5wizard

 

[unclebrian]

Creating a file system with no previously created Logical Volume automatically creates a Logical Volume for you. The problem with this method is that you have no control over were on the disk this Logical Volume is created or what name it is given. If you have more than one disk in the Volume Group you have no control over which disk the Logical Volume is created on.

Recommended method is to create LV first and then add a file system to a previously created LV.

I can't see how to do this with WSM but it can be done using SMIT.

 

[nyck]

I have given this a go using wsm and i can see no way to be able to create the file system on the logical volume that i have created. The only option that I'm given under wsm is system default!!!!

So i'm in the process of using SMIT, when creating the logical volume i cannot see anywhere that i can tell SMIT how large to make this logical volume, is there something I'm missing?

 

[unclebrian]

There is a field in the Add Logical Volume which is number of Logical Partitions. This field determines the size of the Logical Volume. The size of the Logical Partitions can e found using the 'lsvg vgname' command under PP Size.

If PP size is 16mb and you assign 10 Logical Partitions the Logical Volume will be 160mb.

 

[mrn]

Nick

I would suggest you have a read of this

http://publib.boulder.ibm.com/infoc...com.ibm.printers.ipmaixinstall/ipr12mst25.htm

It'll give you a good understanding of how this AIX disk system hangs together, I would also suggest you try to learn the command line & / or smit. When using smit you can press F6 to see the command line command.

Mike

"A foolproof method for sculpting an elephant: first, get a huge block of marble, then you chip away everything that doesn't look like an elephant."

http://www.airport-parking-site.co.uk/

 

[nyck]

hello,

cheers for all the responses, i'm now happy with what i'm doing with this!!

its time i book myself on an AIX course i think to refresh myself with with!