[linux-lvm] Extending the Root Volume with LVM

[linux-lvm] Extending the Root Volume with LVM

[Sean McGlynn]

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I am working with 
RHEL 4 Update 4.  When initially installing the OS I allowed the installation to 
automatically partition the disk, and it used LVM to create a logical volume to 
mount the root file system.  The only other logical volume it created was for 
the swap file.

 

Now, as an 
experiment, I am attempting to extend the volume group and logical volume on 
which root is mounted.  Everything appeared to be going smoothly (extending the 
VG, extending the LV, doing a vgchange, and then a lvm lvchange), but I am now 
at the point where I want to run e2fsck to check the file system and resize2fs 
to resize the files system to realize the added space, and I can't do either 
because the volume is mounted, and cannot be unmounted.

 

I've read a few 
suggestions such as using the installation media to go in in rescue mode, but 
nothing seems to do the trick.  I also read something that said that you cannot 
extend the root volume, and that you shouldn't have to.  This appears to be more 
accurate than anything else I've read.

 

Is it the case that 
you cannot extent the root volume, and if so, why would RHEL configure the root 
volume using LVM if you can't?  If I am missing something, I would greatly 
appreciate someone pointing out what I'm missing.

 

Thank 
you.





 
____________________________________________________________________________________
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See all the new 2007 cars at Yahoo! Autos.
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[linux-lvm] Re: Extending the Root Volume with LVM

[Duane Clark]

Sean McGlynn wrote:
> I am working with RHEL 4 Update 4.  When initially installing the OS I 
> allowed the installation to automatically partition the disk, and it 
> used LVM to create a logical volume to mount the root file system.  The 
> only other logical volume it created was for the swap file.
>  
> Now, as an experiment, I am attempting to extend the volume group and 
> logical volume on which root is mounted.  Everything appeared to 
> be going smoothly (extending the VG, extending the LV, doing a vgchange, 
> and then a lvm lvchange), but I am now at the point where I want to run 
> e2fsck to check the file system and resize2fs to resize the files system 
> to realize the added space, and I can't do either because the volume is 
> mounted, and cannot be unmounted.
>  
> I've read a few suggestions such as using the installation media to go 
> in in rescue mode, but nothing seems to do the trick. 

Why, what problems did you run into? When rescue mode asked you whether 
you wanted it to find and mount the root partitions, did you select 
"skip"? Here are step by step instructions on how I reduced the LVM (on 
FC4), including e2fsck and resize2fs.

https://www.redhat.com/archives/linux-lvm/2006-August/msg00081.html

> I also read 
> something that said that you cannot extend the root volume, and that you 
> shouldn't have to.  This appears to be more accurate than anything else 
> I've read.

Definitely not true.

[linux-lvm] Re: Extending the Root Volume with LVM

[Duane Clark]

Sean McGlynn wrote:
> I am working with RHEL 4 Update 4.  When initially installing the OS I 
> allowed the installation to automatically partition the disk, and it 
> used LVM to create a logical volume to mount the root file system.  The 
> only other logical volume it created was for the swap file.
>  
> Now, as an experiment, I am attempting to extend the volume group and 
> logical volume on which root is mounted.  Everything appeared to 
> be going smoothly (extending the VG, extending the LV, doing a vgchange, 
> and then a lvm lvchange), but I am now at the point where I want to run 
> e2fsck to check the file system and resize2fs to resize the files system 
> to realize the added space, and I can't do either because the volume is 
> mounted, and cannot be unmounted.
>  
> I've read a few suggestions such as using the installation media to go 
> in in rescue mode, but nothing seems to do the trick. 

Why, what problems are you running into? When rescue mode asked if you 
wanted it to find and mount the filesystems, did you select "skip"? Here 
is step by step how I reduced the LVM on FC4, including e2fsck and 
resize2fs:

https://www.redhat.com/archives/linux-lvm/2006-August/msg00081.html

> I also read 
> something that said that you cannot extend the root volume, and that you 
> shouldn't have to.  This appears to be more accurate than anything else 
> I've read.

Definitely not true. I have used the above technique on several drives.

Re: [linux-lvm] Extending the Root Volume with LVM

[Luca Berra]

On Mon, Feb 12, 2007 at 12:11:30PM -0800, Sean McGlynn wrote:
>
>
>I am working with 
>RHEL 4 Update 4.  When initially installing the OS I allowed the installation to 
...
>Now, as an 
>experiment, I am attempting to extend the volume group and logical volume on 
>which root is mounted.  Everything appeared to be going smoothly (extending the 
>VG, extending the LV, doing a vgchange, and then a lvm lvchange), but I am now 
>at the point where I want to run e2fsck to check the file system and resize2fs 
>to resize the files system to realize the added space, and I can't do either 
>because the volume is mounted, and cannot be unmounted.
>
>I've read a few 
you probablu missed to "read the fine manual(TM)" provided with your rhel.
or the fine release notes

rhel 4 supports online resize of filesystem, check the man page of
ext2online to find more.

L.

-- 
Luca Berra -- bluca@comedia.it
        Communication Media & Services S.r.l.
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Re: [linux-lvm] Re: Extending the Root Volume with LVM

[Chris Osicki]

Clark

Have a look at ext2online. It comes with RHEL 4.

Regards,
Chris

On Mon, 12 Feb 2007 12:35:45 -0800
Duane Clark <dclark@akamail.com> wrote:

> Sean McGlynn wrote:
> > I am working with RHEL 4 Update 4.  When initially installing the OS I 
> > allowed the installation to automatically partition the disk, and it 
> > used LVM to create a logical volume to mount the root file system.  The 
> > only other logical volume it created was for the swap file.
> >  
> > Now, as an experiment, I am attempting to extend the volume group and 
> > logical volume on which root is mounted.  Everything appeared to 
> > be going smoothly (extending the VG, extending the LV, doing a vgchange, 
> > and then a lvm lvchange), but I am now at the point where I want to run 
> > e2fsck to check the file system and resize2fs to resize the files system 
> > to realize the added space, and I can't do either because the volume is 
> > mounted, and cannot be unmounted.
> >  
> > I've read a few suggestions such as using the installation media to go 
> > in in rescue mode, but nothing seems to do the trick. 
> 
> Why, what problems did you run into? When rescue mode asked you whether 
> you wanted it to find and mount the root partitions, did you select 
> "skip"? Here are step by step instructions on how I reduced the LVM (on 
> FC4), including e2fsck and resize2fs.
> 
> https://www.redhat.com/archives/linux-lvm/2006-August/msg00081.html
> 
> > I also read 
> > something that said that you cannot extend the root volume, and that you 
> > shouldn't have to.  This appears to be more accurate than anything else 
> > I've read.
> 
> Definitely not true.
> 
> _______________________________________________
> 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/
> 

[linux-lvm] Re: Extending the Root Volume with LVM

[Duane Clark]

Chris Osicki wrote:
> Clark
> 
> Have a look at ext2online. It comes with RHEL 4.

I'll admit I was unaware of that command. I notice that the third 
sentence of the man page says "It is only possible to enlarge a mounted 
filesystem". While Sean was indeed increasing the size, I was trying to 
reduce it.

<just a bit of venting, so feel free to ignore>
A big pain with Linux, in my view, is that even after using it for six 
years, I am unaware of the majority of features available in it. I did 
what I thought was reasonable; I read the HOWTO (the one mentioned down 
there at the bottom of this email ;). No mention of ext2online there, 
nor any mention of the steps I used to resize a root filesystem; only 
the steps for a filesystem that can be easily unmounted while the OS is 
running.

And in order to figure out the steps to resize the root filesystem, I 
read through a lot of man pages and web pages and howtos, and nowhere do 
I recall coming across ext2online (though I'll admit that was awhile 
ago). By the way, I suggested in my posting that the steps be added to 
the howto (the subject line was "Howto suggestion..."). And I have seen 
other postings here with suggestions about the howto.