Re: [linux-lvm] Adding a disk to expand an existing logical volume

From: Ray Morris <support@bettercgi.com>
To: LVM general discussion and development <linux-lvm@redhat.com>
Subject: Re: [linux-lvm] Adding a disk to expand an existing logical volume
Date: Wed, 19 May 2010 12:35:30 -0500	[thread overview]
Message-ID: <1274290530.16893.13@raydesk1.bettercgi.com> (raw)
In-Reply-To: <05d201caf776$17abb110$47031330$@com> (from k@kevinkevin.com on Wed May 19 12:09:48 2010)

> lvextend -L+144G /dev/VolGroup00/my_volume

    If you want to use all available space:

lvextend -L+100%FREE /dev/VolGroup00/my_volume


> I should note that this is a logical volume for a
> collection of Xen virtualized environments so its
> not an actual EXT3 filesystem. I wouldnâ€™t need to
> run the last step I imagine.

   Typically Xen images are files on the filesystem
of the host, so yes, you'd need to resize the host
filesystem, if you are creating Xen image files. Howver,
as long as you are making changes to your LVM, there is
another way which we use, because we think it's better.
Rather than having one huge LV which contains files which
are accessed as though they were block devices, we create
a LV for each guest.  If you have only one big LV, that's
kind of pointless indirection, overhead that gains you
nothing.  It's also problematic for recovery because
you have multiple overlapping ext3 filesystems - one
inside the other, meaning that recovery utilities will
find bogus superblocks belonging to the wrong filesystem.
--
Ray Morris
support@bettercgi.com

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On 05/19/2010 12:09:48 PM, kevin wrote:
> One last thing I want to confirm is the lvextend command to 'grow' the
> logical volume :
> 
> 
> lvextend -L+144G /dev/VolGroup00/my_volume
> 
> After all said steps in previous messages on this thread are  
> complete, is
> the above command correct for my particular scenario? Do I want to  
> 'extend'
> the volume size or 'grow' it?
> 
> Not sure what the difference is.
> 
> 
> ~k
> 
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> 
>