To that end I have started to work on realigning the templates for linux hosts. I have worked up a quick idea of how to make this work, we'll see how it goes.

• convert template to VM
• add an identical sized disk
• boot VM
• use fdisk to set the partition info on second drive correctly
• reboot system to PLD
• dd if=/dev/sda1 of=/dev/sdb1
• dd if=/dev/sda2 of=/dev/sdb2
• fdisk /dev/sdb to verify
• use VMwIC to rearange the disks such that our sdb is used to boot
• boot to RHEL5 disk
• run GRUB sequence to set hd0 etc..
• reboot on new disk ..

Hope it works!

All this is to avoid another dredded install :-) And of course its fun to monkey with disks like this.

But I just made it a bit quicker with my latest template.

The use of LVM is pretty slick for disk type stuff and I was amazed how simple it was to resize and work with the system and other disks. I have just stream-lined my disk growing process by locating the swap space on a LV rather than out on a separate disk partition. This makes the growing of a system disk especially quick and simple.

• Do the initial low level work with fdisk /dev/sda. This will be resizing only /dev/sda2 to the max cylinders. Reboot to sync new partitions.
• Now we just have to run pvresize and lvresize.
  > pvscan
    PV /dev/sda2 VG VolGroup00 lvm2 [14.88 GB / 0 free]
    Total: 1 [14.88 GB] / in use: 1 [14.88 GB] / in no VG: 0 [0 ]
  > pvresize /dev/sda2
    Physical volume "/dev/sda2" changed
    1 physical volume(s) resized / 0 physical volume(s) not resized
  > lvscan
    ACTIVE '/dev/VolGroup00/LogVol00' [10.97 GB] inherit
    ACTIVE '/dev/VolGroup00/LogVol01' [3.91 GB] inherit
  > lvresize -l +100%FREE /dev/VolGroup00/LogVol00
    Extending logical volume LogVol00 to 27.97 GB
    Logical volume LogVol00 successfully resized
  > lvscan
    ACTIVE '/dev/VolGroup00/LogVol00' [27.97 GB] inherit
    ACTIVE '/dev/VolGroup00/LogVol01' [3.91 GB] inherit
  

By placing the swap on the same PV as the / we don't have to muck with moving the swap around any longer. And by using the -l +100%FREE option on the lvresize command it lets lvresize do the work of giving us the whole chunk of new disk.

Well it speed thing up a little anyway..

Running RHEL provided os on a non critical system is somewhat overkill IMHO. So I find the simplest solution is to convert these types of hosts to CentOS based systems, after all its the exact same code base.

So here's the quick and dirty instructions to do this:

Get things ready (as root)

Download what you will need. Pick a mirror

Remove RHEL bindings

Install the CentOS parts

Your now following CentOS instead of RHEL. Reboot if you want. Update at will.