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23.6. Storage Devices

You can install Red Hat Enterprise Linux on a large variety of storage devices. For System z, select Specialized Storage Devices
Storage devices
Select specialized storage devices with a radio button
Figure 23.3. Storage devices

Basic Storage Devices
This option does not apply to System z.
Specialized Storage Devices
Select Specialized Storage Devices to install Red Hat Enterprise Linux on the following storage devices:
  • Direct access storage devices (DASDs)
  • Multipath devices such as FCP-attachable SCSI LUN with multiple paths
  • Storage area networks (SANs) such as FCP-attachable SCSI LUNs with a single path
Use the Specialized Storage Devices option to configure Internet Small Computer System Interface (iSCSI) and FCoE (Fiber Channel over Ethernet) connections.

23.6.1.  The Storage Devices Selection Screen

The storage devices selection screen displays all storage devices to which anaconda has access.
Devices are grouped under the following tabs:
Basic Devices
Basic storage devices directly connected to the local system, such as hard disk drives and solid-state drives. On System z, this contains activated DASDs.
Firmware RAID
Storage devices attached to a firmware RAID controller. This does not apply to System z.
Multipath Devices
Storage devices accessible through more than one path, such as through multiple SCSI controllers or Fiber Channel ports on the same system.
Other SAN Devices
Any other devices available on a storage area network (SAN) such as FCP LUNs attached over one single path.
Select storage devices — Basic Devices
The Basic Devices tab
Figure 23.4. Select storage devices — Basic Devices

Select storage devices — Multipath Devices
The Multipath Devices tab
Figure 23.5. Select storage devices — Multipath Devices

Select storage devices — Other SAN Devices
The Other SAN Devices tab
Figure 23.6. Select storage devices — Other SAN Devices

The storage devices selection screen also contains a Search tab that allows you to filter storage devices either by their World Wide Identifier (WWID) or by the port, target, or logical unit number (LUN) at which they are accessed.
The Storage Devices Search Tab
The tab contains a drop-down menu to select between searching by port, target, and LUN (with corresponding text boxes for these values) and searching by WWID (with a corresponding text box for this value).
Figure 23.7. The Storage Devices Search Tab

The tab contains a drop-down menu to select searching by port, target, WWID, or LUN (with corresponding text boxes for these values). Searching by WWID or LUN requires additional values in the corresponding text box.
Each tab presents a list of devices detected by anaconda, with information about the device to help you to identify it. A small drop-down menu marked with an icon is located to the right of the column headings. This menu allows you to select the types of data presented on each device. For example, the menu on the Multipath Devices tab allows you to specify any of WWID, Capacity, Vendor, Interconnect, and Paths to include among the details presented for each device. Reducing or expanding the amount of information presented might help you to identify particular devices.
Selecting Columns
The drop-down menu in its expanded state
Figure 23.8. Selecting Columns

Each device is presented on a separate row, with a checkbox to its left. Click the checkbox to make a device available during the installation process, or click the radio button at the left of the column headings to select or deselect all the devices listed in a particular screen. Later in the installation process, you can choose to install Red Hat Enterprise Linux onto any of the devices selected here, and can choose to automatically mount any of the other devices selected here as part of the installed system.
Note that the devices that you select here are not automatically erased by the installation process. Selecting a device on this screen does not, in itself, place data stored on the device at risk. Note also that any devices that you do not select here to form part of the installed system can be added to the system after installation by modifying the /etc/fstab file.
when you have selected the storage devices to make available during installation, click Next and proceed to Section 23.7, “Setting the Hostname”

23.6.1.1. DASD low-level formatting

Any DASDs used must be low-level formatted. The installer detects this and lists the DASDs that need formatting.
If any of the DASDs specified interactively in linuxrc or in a parameter or configuration file are not yet low-level formatted, the following confirmation dialog appears:
Unformatted DASD Devices Found
The installer offers to initialize unformatted DASDs.
Figure 23.9. Unformatted DASD Devices Found

To automatically allow low-level formatting of unformatted online DASDs specify the kickstart command zerombr. Refer to Chapter 32, Kickstart Installations for more details.

23.6.1.2.  Advanced Storage Options

From this screen you can configure an iSCSI (SCSI over TCP/IP) target or FCP LUNs. Refer to Appendix B, ISCSI disks for an introduction to iSCSI.
Advanced Storage Options
Advanced Storage Options.
Figure 23.10. Advanced Storage Options

23.6.1.2.1.  Configure iSCSI Parameters
To configure an ISCSI target invoke the 'Configure ISCSI Parameters' dialog by selecting 'Add ISCSI target' and clicking on the 'Add Drive' button. Fill in the details for the ISCSI target IP and provide a unique ISCSI initiator name to identify this system. If the ISCSI target uses CHAP (Challenge Handshake Authentication Protocol) for authentication, enter the CHAP username and password. If your enviroment uses 2-way CHAP (also called "Mutual CHAP"), also enter the reverse CHAP username and password. Click the 'Add target' button to attempt connection to the ISCSI target using this information.
Configure ISCSI Parameters
Configure ISCSI Parameters.
Figure 23.11. Configure ISCSI Parameters

Note that you will be able to reattempt with a different ISCSI target IP should you enter it incorrectly, but to change the ISCSI initiator name you will need to restart the installation.
23.6.1.2.2. FCP Devices
FCP devices enable IBM System z to use SCSI devices rather than, or in addition to, DASD devices. FCP devices provide a switched fabric topology that enables System z systems to use SCSI LUNs as disk devices in addition to traditional DASD devices.
IBM System z requires that any FCP device be entered manually (either in the installation program interactively, or specified as unique parameter entries in the parameter or CMS configuration file) for the installation program to activate FCP LUNs. The values entered here are unique to each site in which they are set up.
Notes
  • Interactive creation of an FCP device is only possible in graphical mode. It is not possible to interactively configure an FCP device in a text-only install.
  • Each value entered should be verified as correct, as any mistakes made may cause the system not to operate properly. Use only lower-case letters in hex values.
  • For more information on these values, refer to the hardware documentation check with the system administrator who set up the network for this system.
To configure a Fiber Channel Protocol SCSI device, select Add ZFCP LUN and click Add Drive. In the Add FCP device dialog, fill in the details for the 16-bit device number, 64-bit World Wide Port Number (WWPN) and 64-bit FCP LUN. Click the Add button to connect to the FCP device using this information.
Add FCP Device
Add FCP device.
Figure 23.12. Add FCP Device

The newly added device should then be present and usable in the storage device selection screen on the Multipath Devices tab, if you have activated more than one path to the same LUN, or on Other SAN Devices, if you have activated only one path to the LUN.

Important — you must define a DASD

The installer requires the definition of a DASD. For a SCSI-only installation, enter none as the parameter interactively during phase 1 of an interactive installation, or add DASD=none in the parameter or CMS configuration file. This satisfies the requirement for a defined DASD parameter, while resulting in a SCSI-only environment.
When you define the DASD as none, you receive an error message such as:
Incorrect format for lower bound of DASD range none: none
It is safe to disregard this error message; installation proceeds as normal.