LVM question

[Aleksandar Milivojevic]

Nitai @ ComputerOil wrote:
> Hi all,
> 
> I have a huge problem, with that I installed on a 25GB Partiton WinXP 
> and then run the FC3 installer. With disk Druid I made a partition for 
> swap (2GB), one for /boot, one for /home (10GB) and another for / 
> (10GB). So, this made up another 25GB of my HardDisk.
> 
> Now the problem ist that I have a 80GB HardDisk and that I have another 
> FreeSpace of 29GB which I somehow cant access anymore, because the Linux 
> Installer made the /, swap and /home to a LVM Volume.
> 
> Does anymore know how I can get the remaining 29GB back? Better would be 
> to have them as Fat32 partitioned so I can access them with WinXP.

...

> vgdisplay:
> 
> --- Volume group ---
>  VG Name               VolGroup00
>  VG Size               50.00 GB
>  PE Size               32.00 MB
>  Total PE              1600
>  Alloc PE / Size       688 / 21.50 GB
>  Free  PE / Size       912 / 28.50 GB

This is strange.  Have you used "autopartition" feature, or have you 
created partitions completely by hand?  If you used "autopartition" 
feature, maybe you should make a bug report.  If you created them by 
hand, well, than the only possibility is that you told installer to use 
all available space for LVM partition.

I don't think there's much you can do now, since pvresize command is not 
yet implemented.  If you have 20GB+ disk somewhere, you might try 
popping it into the machine and doing something as described below.  If 
you don't, your only option might be to reinstall Linux from scratch, 
but this time, make sure you size your partitions appropriately.

I'll assume new disk is /dev/hdb, and you are going to create single 
primary partition /dev/hdb1.

Also, from the above output, it is not visible on which partition your 
current physical volume is.  Output of "pvdisplay" or "p" command in 
fdisk would show that.  I'll assume it is /dev/hda3 (probably isn't).

Change device names appropriately.

# fdisk /dev/hdb

create partition on it, and mark it as type 8e (Linux  LVM).  The size 
must be at least what "Alloc PE / Size" line from vgdisplay output says.

Now, import the partition into LVM (create physical volume on it):

# pvcreate /dev/hdb1

Add this new physical volume to volume group

# vgextend VolGroup00 /dev/hdb1

Remove the "old" physical volume.  This will probably take some time to 
complete (20GB+ of data needs to be moved from one disk to another):

# vgreduce VolGroup00 /dev/hda3  <- change to match your real PV

Remove the "old" partition from LVM system:

# pvremove /dev/hda3             <- same thing

Repartition the disk:

# fdisk /dev/hda

delete partition where PV was, create new one with correct size (which, 
again, must be at least what "Alloc PE / Size" line from vgdisplay 
output says).  Make sure you tag partition as type 8e (Linux LVM).  You 
may also create new FAT32 partition in this step.  Make sure you tag 
that partition as type b (FAT32).

Now, this steps are basically the same thing as above.  We are just 
moving things where they were, so that you can remove second disk from 
the system.

# pvcreate /dev/hda3
# vgextend VolGroup00 /dev/hda3
# vgreduce VolGroup00 /dev/hdb1
# pvremove /dev/hdb1

-- 
Aleksandar Milivojevic <amilivojevic at pbl.ca>    Pollard Banknote Limited
Systems Administrator                           1499 Buffalo Place
Tel: (204) 474-2323 ext 276                     Winnipeg, MB  R3T 1L7