topic Re: Creating a logical volume from shell? in Operating System - HP-UX

Creating a logical volume from shell?

rmueller58 — Fri, 11 Jun 2004 14:44:15 GMT

I am working on adding multiple logical volumes, I can use SAM however I'd prefer to create them from the shell.

I've got multiple volume groups with available space, I have to setup informix databases using RAW space,

how can I create the logical volume below
/dev/vg## without having to go into SAM?

Re: Creating a logical volume from shell?

curt larson_1 — Fri, 11 Jun 2004 14:46:10 GMT

you would use the lvcreate command
see the lvcreate man page for possible options that you'll need to use

Re: Creating a logical volume from shell?

rmueller58 — Fri, 11 Jun 2004 14:49:58 GMT

Curt,
it is pretty cryptic.

From the man page I can see HOW to create one, but on how to point to the Volume Group.. If it is created by default in the correct VG will it work OK?

Re: Creating a logical volume from shell?

Jeff Schussele — Fri, 11 Jun 2004 14:50:51 GMT

Hi rex,

Use the following

lvcreate -L XXXXX -n lv_name /dev/vg_name

where XXXXX=size in MB. If you're going to want a mirror then add -m 1 If you want it striped then add -i x -I YYY where x=number of disks in the stripe (stripe count) & YYY=stripe size in KB (must be power of 2)

HTH,
Jeff

Re: Creating a logical volume from shell?

rmueller58 — Fri, 11 Jun 2004 14:52:25 GMT

Thanks I'll give it a shot..

Re: Creating a logical volume from shell?

Marc Smith — Fri, 11 Jun 2004 14:56:56 GMT

Maybe this is better:

lvcreate -L -n

IIRC, you can leave out the -n switch and it'll create it with a lvol## format.

Then you can check it with:

lvdisplay -v /dev//

If you're not creating raw volumes, you need to do this:

newfs -F vxfs /dev//

Then add it to you fstab and mount it.

Re: Creating a logical volume from shell?

Jeff Schussele — Fri, 11 Jun 2004 14:58:06 GMT

Since you're wanting raw volumes then you can skip the next step of filesystem creation.
You just start using /dev/vg_name/lv_name
But you should consider putting *commented* entries in the /etc/fstab as a reminder or a placeholder if you will for those LVs you've created in those VGs because they'll never show up in a bdf output & can become forgotten over time.

My 2 cents,
Jeff

Re: Creating a logical volume from shell?

Jeff Schussele — Fri, 11 Jun 2004 15:00:34 GMT

Marc's correct - you don't *need* the -n lv_name. It will give you the next lvolX value by default.
BUT I hate that. I want my lv_name to tell me just what the heck that LV's for. I want it to have meaning - not just another number. Just my preference.

Rgds,
Jeff

Re: Creating a logical volume from shell?

Marc Smith — Fri, 11 Jun 2004 15:01:37 GMT

Wow...I don't know how I missed where you said you wanted raw volumes...Oh well, It's Friday. ;)

Re: Creating a logical volume from shell?

rmueller58 — Fri, 11 Jun 2004 15:12:27 GMT

Ok,

I am starting to get confused so let me run this past you all.

for example if I use:
lvcreate -L 1048576 -n plvdbs /dev/vg02

It will create the RAW logical called plvdbs since I am not creating a VXFS?

Re: Creating a logical volume from shell?

Marc Smith — Fri, 11 Jun 2004 15:15:52 GMT

Yep. It's the newfs command that creates the filesystem. You will have a raw volume as long as you don't run newfs.

Sorry for the confusion.

Re: Creating a logical volume from shell?

rmueller58 — Fri, 11 Jun 2004 15:18:28 GMT

cool..

We are heading in an upgrade and need to parallel 22 informix spaces.. I will script it and be done with it..

Re: Creating a logical volume from shell?

Patrick Wallek — Fri, 11 Jun 2004 15:20:56 GMT

What size are you looking for?

The '-L 1048576' will create a 1,048,576 MB = 1,024 GB = 1 TB Volume. Do you want 1 TB?

Re: Creating a logical volume from shell?

rmueller58 — Fri, 11 Jun 2004 15:22:20 GMT

no.. 1 Gb. or 512m for the most of them

Re: Creating a logical volume from shell?

Patrick Wallek — Fri, 11 Jun 2004 15:28:38 GMT

You must remember then that you specify the size with the -L option in MB. So if you want 1 GB (1,024 MB) then it is '-L 1024' and if you want 512 MB then it is '-L 512'.

Re: Creating a logical volume from shell?

rmueller58 — Fri, 11 Jun 2004 15:30:28 GMT

Thanks Patrick for clarifying the size..
And Mark and Jeff for the assist..