Reinitializing only the root partition on SLED

Often times obscure problems with a SLED system can be resolved more quickly by simply reinstalling the root partition. This document is intended to describe the process based on the following assumptions:

1. A standard SLED installation was used to initially install the system or the root partition and the partition containing the user's data files are separate partitions (ie with a standard SLED installation a /home partition is created to store user data).

If the SLED installation is based on one large partition containing both the root data and the user's data the process described in this TID will NOT work.

2. While the document will be as specific with respect to describing the process, users of this document should be familiar with Linux partitioning, specifically as it applies to their specific setup.

3. This process described will completely format the root partition, removing all data it contains. That data will not be recoverable once the format process is started. It is strongly recommended that a current and valid backup of any data on the system be performed prior to following the process outlined in this document.

4. Following the process described in this document should be done with caution and the user assumes all responsibility for any lost data.

Helpful information to gather before beginning the process:

1. The output from fdisk -l is useful in showing what partitions exist on the system:

Disk /dev/sda: 42.9 GB, 42949672960 bytes
255 heads, 63 sectors/track, 5221 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sda1 1 262 2104483+ 82 Linux swap / Solaris
/dev/sda2 * 263 1568 10490445 83 Linux
/dev/sda3 1569 5221 29342722+ 83 Linux

While this information does not specifically show what the partition mount points are it does show that the system contains 3 partitions.

2. the /etc/fstab file is useful for showing parititions and their mount points (note: the following example has been truncated):

/dev/sda2 / reiserfs acl,user_xattr 1 1
/dev/sda3 /home reiserfs acl,user_xattr 1 2
/dev/sda1 swap swap defaults 0 0

The example /etc/fstab file shows the same 3 partitions as listed by thefdisk -l, however, it also shows the mount points associated with those partitions. We now know that the /dev/sda2 partition contains root (ie / ) and the /dev/sda3 partition contains the /home partition.

From this information it has been determined that a reinitialization/reinstall of the just the root partition is possible (ie the root partition and the user data partition are maintained separately).

The Process

1.Boot the system using the original installation media (ie a SLED 10 SP2 DVD, etc.) selecting Installation when the menu appears
2.Select the appropriate language and press Next
3.Select “Yes” for the license and press Next
4.On the Installation Mode screen select “New Installation” and press Next
5.On the Clock and Time Zone screen select the appropriate information and press Next
6.On the Installation Settings screen click on the “Partitioning” link

7.On the Suggested Partitioning screen select “Create Custom Partition Setup” and press Next
8.On the Preparing Hard Disk: Step 1 screen select “Custom Partitioning (for experts) and press Next
9.The following screen (ie “Expert Partitioner” screen) shows the partitions as they exist on the hard drive.  Using the information from the /etc/fstab file we know that the /dev/sda2 device contains the root partition and the /dev/sda3 device contains the /home partition.  See the following screen capture.

10.Highlight the /dev/sda2 (or the device that corresponds to the root partition) and select Edit
11.On the Edit Existing Partition screen for the /dev/sda2 device select “Format” and change the Mount Point to / and then press OK.

12.On the Edit Existing Partition screen highlight the /dev/sda3 device (or the device that corresponds to the home partition) and select Edit
13. On the Edit Existing Partition screen for the /dev/sda3 device make sure that “Do not format” is selected and change the Mount Point to /home (this would have been the setting if partitioning was not modified in the initial install, refer back to step 2 to ensure the partition on your machine was in fact /home or change it to the appropriate setting for your installation) and then press OK.

14.On the expert Partitioner screen select Finish to save the changes.
15.The Installation Settings screen should now look like this (Note that only the /dev/sda2 partition containing / is set to be formated):

16.Verify the settings and then press “Accept”
17.Proceed through the installation as normal.  When the user creation screen appears if the same user login name is used a message will popup stating the user home directory already exists and asks if you would like to use it and change the rights.  Select “yes” and the home directory access rights will be changed to the new user.