[linux-lvm] LVM question on move and resize

[linux-lvm] LVM question on move and resize

[John Koshi]

Hello,

I have the following setup:

HP dv1000 laptop with an 80G hard disk laid out as follows:
1)70Gb NTFS, WinXP primary
2)100Mb ext3 primary Fedora 4 /boot
3)10Gb Extd primary, containing logical(8E) LVM Fedora 4 root

Since the Linux root is getting full, I want to expand it,
by reducing the NTFS partition, and moving all the Linux
partitions down, and then expand the LVM root outwards.

With Partition Magic 8.0, I can resize the NTFS disk, and
move the ext3 boot partition (after removing it's features
resize_inode, dir_index, and ext_attr using e2fsprogs),
and resize the Extended partition to the left as needed.

The problem now is how to move and expand the LVM root as
mentioned above. Partition Magic and Qtparted can't do it.

Is it possible to do this? If so, what are the steps?

regards,
John

Re: [linux-lvm] LVM question on move and resize

[Dieter Stüken]

John Koshi wrote:
> Hello,
> 
> I have the following setup:
> 
> HP dv1000 laptop with an 80G hard disk laid out as follows:
> 1)70Gb NTFS, WinXP primary
> 2)100Mb ext3 primary Fedora 4 /boot
> 3)10Gb Extd primary, containing logical(8E) LVM Fedora 4 root
> 
> Since the Linux root is getting full, I want to expand it,
> by reducing the NTFS partition, and moving all the Linux
> partitions down, and then expand the LVM root outwards.
> 
> With Partition Magic 8.0, I can resize the NTFS disk, and
> move the ext3 boot partition (after removing it's features
> resize_inode, dir_index, and ext_attr using e2fsprogs),
> and resize the Extended partition to the left as needed.
> 
> The problem now is how to move and expand the LVM root as
> mentioned above. Partition Magic and Qtparted can't do it.
> 
> Is it possible to do this? If so, what are the steps?

can you send us a "fdisk -l" of your partition layout?

Why moving your LVM?

After you shrunk the leading partitions, you should get a gap
below your LVM partition. Can you fit a new partition into this gap?
There after you format this new partition as an additional PV
using "pvcreate" and extend your VG using vgextend.

Now your VG extends over both partitions, and you may use the new
space to extend any LV within your VG. LVM does not care about
how the available disk spaces (its PVs) is organized nor has it
to be contiguous. It may even spread over several disks.

This is the reason why LVM is much more flexible than DOS partitions
and Partition Magic will ever be.

Dieter.

Re: [linux-lvm] LVM question on move and resize

[John Koshi]

Dieter,

Thanks very much for your prompt reply.

I went ahead and committed the changes using
Partition Magic, as described earler, and now
have the following:

Note: the /dev/hda2 at the very end of the disk
      is the instant DVD play (Linux) partition
      that came with the laptop's XP install.
=============================================================================
[root@sonata /]# fdisk -l
omitting empty partition (5)
Disk /dev/hda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
   Device Boot      Start         End      Blocks   Id  System
/dev/hda1   *           1        5201    41777001    7  HPFS/NTFS
/dev/hda2            9704        9729      208845   88  Linux plaintext
/dev/hda3            5202        5214      104422+  83  Linux
/dev/hda4            5215        9703    36057892+   f  W95 Ext'd (LBA)
/dev/hda5            8425        9703    10273536   8e  Linux LVM
Partition table entries are not in disk order
-----------------------------------------------------------------------------
[root@sonata /]# df -lH
Filesystem             Size   Used  Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
                       8.2G   5.7G   2.1G  74% /
/dev/hda3              104M    13M    86M  14% /boot
/dev/shm               526M      0   526M   0% /dev/shm
=============================================================================

Both Linux and Windows boot up correctly, without any
further changes. 

I assume the next steps will be (from a rescue CD):

1) Use fdisk to format the unused 25 Gb space in the
   extended partition, to a new type 8E partition.
2) Use pvcreate to create a new physical vol there.
3) Use vgextend to extend VolGroup00 to include the
   new physical volume.
4) Use lvextend to extend LogVol00 by the XX Gb.
5) Do a file system check of LogVol00.

Does this look right? Am I missing any steps?

Thanks again for your help.

regards,
John



--- Dieter St�ken <stueken@conterra.de> wrote:

> John Koshi wrote:
> > Hello,
> > 
> > I have the following setup:
> > 
> > HP dv1000 laptop with an 80G hard disk laid out as follows:
> > 1)70Gb NTFS, WinXP primary
> > 2)100Mb ext3 primary Fedora 4 /boot
> > 3)10Gb Extd primary, containing logical(8E) LVM Fedora 4 root
> > 
> > Since the Linux root is getting full, I want to expand it,
> > by reducing the NTFS partition, and moving all the Linux
> > partitions down, and then expand the LVM root outwards.
> > 
> > With Partition Magic 8.0, I can resize the NTFS disk, and
> > move the ext3 boot partition (after removing it's features
> > resize_inode, dir_index, and ext_attr using e2fsprogs),
> > and resize the Extended partition to the left as needed.
> > 
> > The problem now is how to move and expand the LVM root as
> > mentioned above. Partition Magic and Qtparted can't do it.
> > 
> > Is it possible to do this? If so, what are the steps?
> 
> can you send us a "fdisk -l" of your partition layout?
> 
> Why moving your LVM?
> 
> After you shrunk the leading partitions, you should get a gap
> below your LVM partition. Can you fit a new partition into this gap?
> There after you format this new partition as an additional PV
> using "pvcreate" and extend your VG using vgextend.
> 
> Now your VG extends over both partitions, and you may use the new
> space to extend any LV within your VG. LVM does not care about
> how the available disk spaces (its PVs) is organized nor has it
> to be contiguous. It may even spread over several disks.
> 
> This is the reason why LVM is much more flexible than DOS partitions
> and Partition Magic will ever be.
> 
> Dieter.
> 
> _______________________________________________
> 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/
> 

Re: [linux-lvm] LVM question on move and resize

[Dieter Stüken]

John Koshi wrote:
> I assume the next steps will be (from a rescue CD):
> 
> 1) Use fdisk to format the unused 25 Gb space in the
>    extended partition, to a new type 8E partition.
> 2) Use pvcreate to create a new physical vol there.
> 3) Use vgextend to extend VolGroup00 to include the
>    new physical volume.
> 4) Use lvextend to extend LogVol00 by the XX Gb.
> 5) Do a file system check of LogVol00.
> 
> Does this look right? Am I missing any steps?

after you grow LogVol00 you also have to expand the
ext2/ext2 filesystem inside (step 4a)

resize2fs -p /dev/mapper/VolGroup00-LogVol00

This actually does the real work. resize2fs recommends
to perform an fsck before. If you are in doubt, do it,
else you may skip this using "resize2fs -f -p".

You don't have to supply a size, resize2fs will find
the current size of the extended volume auomatically

Will you perform this while booting from a rescue CD?
If this is your root filesystem you have to, anyway.
Else you possibly have to reboot, after changing the
partition table, because it may be locked by the system
while it is in use.

Tip: you may rename your VG and your LVs to get expressive
names like "/dev/mapper/Sonota-Root". Imo this is less 
error prone than working with technical names like "LogVol42".

> Disk /dev/hda: 80.0 GB, 80026361856 bytes
> 255 heads, 63 sectors/track, 9729 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
>    Device Boot      Start         End      Blocks   Id  System
> /dev/hda1   *           1        5201    41777001    7  HPFS/NTFS
> /dev/hda2            9704        9729      208845   88  Linux plaintext
> /dev/hda3            5202        5214      104422+  83  Linux
> /dev/hda4            5215        9703    36057892+   f  W95 Ext'd (LBA)
> /dev/hda5            8425        9703    10273536   8e  Linux LVM
> Partition table entries are not in disk order

So you end up with an extended partition containing your LVM.
Even if this works, it is an ugly solution. This Win95 extended
partition hack is something like a poor-mans LVM with partition
magic as its management tool.
 
It would be much better, to REPLACE the extended partition by LVM. Unfortunately I don't see any easy migration path without an external
disk. If you have any spare disk, to temporary hold the 8.2Gb root
volume, I may point out an other solution.

Dieter.

Re: [linux-lvm] LVM question on move and resize

[John Koshi]

Hi Dieter,

Thanks for your e-mail. I did go through the steps as
mentioned, including the resize2fs after the fsck, and
everything worked fine. The one other thing I had to do
was to initially create the new partition in the empty
space, first as ext2, and then move to type 8e/LVM.

You're right about the W95 extended partition. It is
pretty ugly! But I had to consider the /dev/hda2 Linux
partition at the end of the disk, which handles the
quick-play feature of the HP laptop. I did not want to
lose that in the process of adding Linux/dual-boot, so
I went with Partition Magic for this.

Actually I do have a large USB disk (Seagate 160GB)
and had considered using it during this expansion of 
the Linux installation. I'm interested in seeing your
solution, in this case.

Thanks again.

regards,
John



--- Dieter St�ken <stueken@conterra.de> wrote:

> John Koshi wrote:
> > I assume the next steps will be (from a rescue CD):
> > 
> > 1) Use fdisk to format the unused 25 Gb space in the
> >    extended partition, to a new type 8E partition.
> > 2) Use pvcreate to create a new physical vol there.
> > 3) Use vgextend to extend VolGroup00 to include the
> >    new physical volume.
> > 4) Use lvextend to extend LogVol00 by the XX Gb.
> > 5) Do a file system check of LogVol00.
> > 
> > Does this look right? Am I missing any steps?
> 
> after you grow LogVol00 you also have to expand the
> ext2/ext2 filesystem inside (step 4a)
> 
> resize2fs -p /dev/mapper/VolGroup00-LogVol00
> 
> This actually does the real work. resize2fs recommends
> to perform an fsck before. If you are in doubt, do it,
> else you may skip this using "resize2fs -f -p".
> 
> You don't have to supply a size, resize2fs will find
> the current size of the extended volume auomatically
> 
> Will you perform this while booting from a rescue CD?
> If this is your root filesystem you have to, anyway.
> Else you possibly have to reboot, after changing the
> partition table, because it may be locked by the system
> while it is in use.
> 
> Tip: you may rename your VG and your LVs to get expressive
> names like "/dev/mapper/Sonota-Root". Imo this is less 
> error prone than working with technical names like "LogVol42".
> 
> > Disk /dev/hda: 80.0 GB, 80026361856 bytes
> > 255 heads, 63 sectors/track, 9729 cylinders
> > Units = cylinders of 16065 * 512 = 8225280 bytes
> >    Device Boot      Start         End      Blocks   Id  System
> > /dev/hda1   *           1        5201    41777001    7  HPFS/NTFS
> > /dev/hda2            9704        9729      208845   88  Linux plaintext
> > /dev/hda3            5202        5214      104422+  83  Linux
> > /dev/hda4            5215        9703    36057892+   f  W95 Ext'd (LBA)
> > /dev/hda5            8425        9703    10273536   8e  Linux LVM
> > Partition table entries are not in disk order
> 
> So you end up with an extended partition containing your LVM.
> Even if this works, it is an ugly solution. This Win95 extended
> partition hack is something like a poor-mans LVM with partition
> magic as its management tool.
>  
> It would be much better, to REPLACE the extended partition by LVM.
> Unfortunately I don't see any easy migration path without an external
> disk. If you have any spare disk, to temporary hold the 8.2Gb root
> volume, I may point out an other solution.
> 
> Dieter.
> 
> _______________________________________________
> 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/
> 

Re: [linux-lvm] LVM question on move and resize

[Dieter Stüken]

John Koshi wrote:
> Actually I do have a large USB disk (Seagate 160GB)
> and had considered using it during this expansion of 
> the Linux installation. I'm interested in seeing your
> solution, in this case.

Hi John,

i frequently reorganized my data by extending my VG by 
a new disk (vgextend) and moved all data off the unwanted
disk using "vgmove". Afterwards I may unplug the unwanted disk
from my VG (vgreduce). All this may be performed, while people
are working on this server! But I'm using hot-plugable
SATA disks on a raid controller.

But you talk about a laptop and an USB disk, and the device to
replace is an extended partition, not a hot pluggable SATA disk.
So I think there are too much traps in your case to fail.

Instead I would simply install a plain ext2 partition on the
USB disk, mount it and copy all data using simple "cp -a" to
the USB disk. Then erase hda4 and recreate it as a plain primary
partition, install LVM again and copy the data back. This is
not as fancy as using LVM, but much saver in your case.

After all I even think: it may be currently ugly, but it works. 
So may be you should keep this setup until you really need
to change it.

regards, Dieter.