In some cases, you may need to erase the contents of a disk (or "clear" a disk) before being able to provision a system.

 

The examples below for for sda. Replace sda with sd{b,c,d} for other drives

 

To erase the disk's content, set the BIOS to Network Boot first, then deploy Live Ubuntu.

 

 

Key "3" to Go to Menu, and hit "Enter"

 

Select "cmd" to open a command line terminal:

 

 

Switch to root user:

# sudo su -

 

Optional - start a script file that can be read on the Provisioner PXE Server:

# script /tmp/liveUbuntu/{descriptive-name}.script

For example, find the file for Client system with MAC address 00:50:56:3d:ff:95 in:

/home/tftpboot/pub/liveUbuntu/clientSystemProfiles/00-50-56-3d-ff-95/{descriptive-name}.script

 

See drive layout

# sfdisk -l

 

Clear the MBR

# dd if=/dev/zero of=/dev/sda bs=512 count=8

Normally, clearing the MBR is all that is needed unless the drive is corrupt up or has an unrecognized file system on it. Then a wipe of the entire disk is required.

Clear the entire drive (this may take considerable time)

# dd if=/dev/zero of=/dev/sda bs=1M

 

Check the disk:

# sfdisk -l

 

Reset the drive partitions

# sfdisk -f /dev/sda

* note the number of cylinders

 

For use with Windows, ",07" is used for the Windows NTFS file system format format

# 0,{sda-number-of-cylinders},07,* # 0,0 # 0,0 # 0,0

 

For use with Linux, no "'07" is needed

# 0,{sda-number-of-cylinders},,*

# 0,0

# 0,0

# 0,0

 

8) Check it

# sfdisk -l

 

If the script option was used, end the script action with <Cntl-D>

 

Power off the client and follow the instructions:

# poweroff

 

Finally, reset your BIOS if required:

•For Windows and Linux, keep the boot sequence "Network boot then hard drive"

•For ESX and ESXi, set the boot sequence to "Hard drive first, then network boot"

 

Note for UCS Manager: disassociating then re-associating the Blade's or Server's Service Profile provides a clean disk from which to start, so no Live-Ubuntu operations are typically needed.

 

 

Examples

 

Linux system before:

# sfdisk -l

Disk /dev/sda: 5221 cylinders, 255 heads, 63 sectors/track Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0

Device Boot Start   End  #cyls  #blocks  Id System

/dev/sda1  *   0+   12   13-  104391      83 Linux

/dev/sda2     13   143   131  1052257+    82 Linux swap / Solaris

/dev/sda3    144  5220  5077  40781002+   83 Linux

/dev/sda4     0    -    0     0  0        Empty

 

Linux system after - all on sda1 with the "Linux" designation is what is needed

# sfdisk -l Disk /dev/sda: 5221 cylinders, 255 heads, 63 sectors/track Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0

 Device Boot Start   End  #cyls  #blocks  Id System

/dev/sda1  *   0+ {last}  {all}   {all}    83 Linux

/dev/sda2     0    -    0     0  0 Empty

/dev/sda3     0    -    0     0  0 Empty

/dev/sda4     0    -    0     0  0 Empty

 

Windows system after - all on sda1 with the "NTFS" designation is what is needed

# sfdisk -l Disk /dev/sda: 5221 cylinders, 255 heads, 63 sectors/track Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0

 Device Boot Start   End  #cyls  #blocks  Id System

/dev/sda1  *  0+     5220  5221   8225280  83 H??/NTFS

/dev/sda2     0    -    0     0   0 Empty

/dev/sda3     0    -    0     0   0 Empty

/dev/sda4     0    -    0     0   0 Empty