Partition Types

Every hard disk has a partition table with space for four entries. An entry in the partition table can correspond to a primary partition or an extended partition. Only one extended partition entry is allowed, however.

A primary partition simply consists of a continuous range of cylinders (physical disk areas) assigned to a particular operating system. With primary partitions only, you would be limited to four partitions per hard disk, because more do not fit in the partition table. This is why extended partitions are used. Extended partitions are also continuous ranges of disk cylinders, but an extended partition may itself be subdivided into logical partitions. Logical partitions do not require entries in the partition table. In other words, an extended partition is a container for logical partitions.

If you need more than four partitions, create an extended partition as the fourth partition or earlier. This extended partition should span the entire remaining free cylinder range. Then create multiple logical partitions within the extended partition. The maximum number of logical partitions is 15 on SCSI, SATA, and Firewire disks and 63 on (E)IDE disks. It does not matter which types of partitions are used for Linux. Primary and logical partitions both work fine.

Required Disk Space

YaST normally proposes a reasonable partitioning scheme with sufficient disk space. If you want to implement your own partitioning scheme, consider the following recommendations concerning the requirements for different system types.

Minimal System: 500 MB

No graphical interface (X Window System) is installed, which means that only console applications can be used. Also, only a very basic selection of software is installed.

The partitions to create depend on the available space. The following are some basic partitioning guidelines:

Up to 4 GB:

One partition for the swap space and one root partition (/). In this case, the root partition must allow for those directories that often reside on their own partitions if more space is available.

4 GB or More:

A swap partition, a root partition (1 GB), and one partition each for the following directories as needed: /usr (4 GB or more), /opt (4 GB or more), and /var (1 GB). If you do not want to have separate partitions for these directories, add the suggested disk space to the root partition. The rest of the available space can be used for /home.

Depending on the hardware, it might also be useful to create a boot partition (/boot) to hold the boot mechanism and the Linux kernel. This partition should be located at the start of the disk and should be at least 8 MB or one cylinder. As a rule of thumb, always create such a partition if it was included in YaST's original proposal. If you are unsure about this, create a boot partition to be on the safe side.

You should also be aware that some (mostly commercial) programs install their data in /opt. Therefore, either create a separate partition for /opt or make the root partition large enough.

Partitioning with YaST

When you select the partitioning item in the suggestion window for the first time, the YaST partitioning dialog displays the proposed partition settings. Accept these current settings as they are or change them before continuing. Alternatively, discard all the settings and start over from scratch.

Nothing in the partitioning setup is changed if you select Accept Proposal. If you select Base Partition Setup on This Proposal, the Expert Partitioner opens. It allows tweaking the partition setup in every detail. This dialog is explained in Section 7.5.6, Partitioner. The original setup as proposed by YaST is offered there as a starting point.

Selecting Create Custom Partition Setup opens the dialog for hard disk selection. Use the list to choose among the existing hard disks on your system. SUSE Linux Enterprise will be installed on the disk selected in this dialog.

The next step is to determine whether the entire disk should be used (Use Entire Hard Disk) or whether to use any existing partitions (if available) for the installation. If a Windows operating system was found on the disk, you are asked whether to delete or resize the partition. Before doing so, read Resizing a Windows Partition. If desired, go to the Expert Partitioner dialog to create a custom partition setup as described in Section 7.5.6, Partitioner.

YaST checks during the installation whether the disk space is sufficient for the software selection made. If not, YaST automatically changes the software selection. The proposal dialog displays a notice to inform you about this. As long as there is sufficient disk space available, YaST simply accepts your settings and partitions the hard disk accordingly.

Resizing a Windows Partition

If a hard disk containing a Windows FAT or NTFS partition is selected as the installation target, YaST offers to delete or shrink this partition. In this way, you can install SUSE® Linux Enterprise even if there is currently not enough space on the hard disk. This functionality is especially useful if the selected hard disk contains only one Windows partition that covers the entire hard disk. This is sometimes the case on computers where Windows comes preinstalled. If YaST sees that there is not enough space on the selected hard disk, but that space could be made available by deleting or shrinking a Windows partition, it presents a dialog in which to choose one of these two options.

Figure 3-2 Possible Options for Windows Partitions

If you select Delete Windows Completely, the Windows partition is marked for deletion and the space is used for the installation of SUSE Linux Enterprise.

To shrink the Windows partition, interrupt the installation and boot Windows to prepare the partition from there. Although this step is not strictly required for FAT partitions, it speeds up the resizing process and also makes it safer. These steps are vital for NTFS partitions.

FAT File System

In Windows, first run scandisk to make sure that the FAT partition is free of lost file fragments and crosslinks. After that, run defrag to move files to the beginning of the partition. This accelerates the resizing procedure in Linux.

If you have optimized virtual memory settings for Windows so a contiguous swap file is used with the same initial (minimum) and maximum size limit, consider another step. With these Windows settings, the resizing might split the swap file into many small parts scattered all over the FAT partition. Also, the entire swap file would need to be moved during the resizing, which makes the process rather slow. It is therefore useful to disable these Windows optimizations for the time being and reenable them after the resizing has been completed.

NTFS File System

In Windows, run scandisk and defrag to move the files to the beginning of the hard disk. In contrast to the FAT file system, you must perform these steps. Otherwise the NTFS partition cannot be resized.

After these preparations, return to the Linux partitioning setup and select Shrink Windows Partition. After a quick check of the partition, YaST opens a dialog with a suggestion for resizing the Windows partition.

Figure 3-3 Resizing the Windows Partition

The first bar graph shows how much disk space is currently occupied by Windows and how much space is still available. The second bar graph shows how the space would be distributed after the resizing, according to YaST's current proposal. See Figure 3-3. Accept the proposed settings or use the slider to change the partition sizing (within certain limits).

If you leave this dialog by selecting Next, the settings are stored and you are returned to the previous dialog. The actual resizing takes place later, before the hard disk is formatted.

Changing the Installation Scope

If you have specific software needs, modify the current selection with the package manager, which greatly eases this task. The package manager offers various filter criteria to simplify selection from the numerous packages in SUSE Linux Enterprise.

The filter selection box is located at the top left under the menu bar. The default filter is Patterns. Patterns install packages based on the intended use or task of your system. The groups included in the current system type are preselected. Click the check boxes to select or deselect groups for installation.

The right part of the window displays a table listing the individual packages included in the current group. The table column furthest to the left shows the current status of each package. Two status flags are especially relevant for the installation: Install (the box in front of the package name is checked) and Do Not Install (the box is empty). To select or deselect individual software packages, click the status box until the desired status is displayed. Alternatively, right-click the package line to access a pop-up menu listing all the possible status settings.

Other Filters

Click the filter selection box to view the other possible filters. The selection according to Package Groups can also be used for the installation. This filter sorts the program packages by subjects in a tree structure to the left. The more you expand the branches, the more specific the selection of packages is and the fewer packages are displayed in the list of associated packages to the right.

Use Search to search for a specific package. This is explained in detail in Section 7.3.1, Installing and Removing Software.

Package Dependencies and Conflicts

You cannot simply install any combination of software packages. The different software packages must be compatible. Otherwise they might interfere with each other and cause conflicts that affect the system as a whole. Therefore, you may see alerts about unresolved package dependencies or conflicts after selecting or deselecting software packages in this dialog. If installing SUSE Linux Enterprise for the first time or if you do not understand the alerts, read Section 7.3.1, Installing and Removing Software, which provides detailed information about the operation of the package manager.

Exiting the Software Selection

When satisfied with your software selection and all package dependencies or conflicts are resolved, click Accept to apply your changes and exit the module. During the installation, the changes are recorded internally and applied later when the actual installation starts.