Appendix B. System requirements reference

This section provides information and guidelines for hardware, installation target, system, memory, and RAID when installing Red Hat Enterprise Linux.

B.1. Hardware compatibility

Red Hat works closely with hardware vendors on supported hardware.

B.2. Supported installation targets

An installation target is a storage device that stores Red Hat Enterprise Linux and boots the system. Red Hat Enterprise Linux supports the following installation targets for AMD64, Intel 64, and 64-bit ARM systems:

  • Storage connected by a standard internal interface, such as SCSI, SATA, or SAS
  • BIOS/firmware RAID devices
  • NVDIMM devices in sector mode on the Intel64 and AMD64 architectures, supported by the nd_pmem driver.
  • Fibre Channel Host Bus Adapters and multipath devices. Some can require vendor-provided drivers.
  • Xen block devices on Intel processors in Xen virtual machines.
  • VirtIO block devices on Intel processors in KVM virtual machines.

Red Hat does not support installation to USB drives or SD memory cards. For information about support for third-party virtualization technologies, see the Red Hat Hardware Compatibility List.

B.3. System specifications

The Red Hat Enterprise Linux installation program automatically detects and installs your system’s hardware, so you should not have to supply any specific system information. However, for certain Red Hat Enterprise Linux installation scenarios, it is recommended that you record system specifications for future reference. These scenarios include:

Installing RHEL with a customized partition layout

Record: The model numbers, sizes, types, and interfaces of the hard drives attached to the system. For example, Seagate ST3320613AS 320 GB on SATA0, Western Digital WD7500AAKS 750 GB on SATA1.

Installing RHEL as an additional operating system on an existing system

Record: Partitions used on the system. This information can include file system types, device node names, file system labels, and sizes, and allows you to identify specific partitions during the partitioning process. If one of the operating systems is a Unix operating system, Red Hat Enterprise Linux may report the device names differently. Additional information can be found by executing the equivalent of the mount command and the blkid command, and in the /etc/fstab file.

If multiple operating systems are installed, the Red Hat Enterprise Linux installation program attempts to automatically detect them, and to configure boot loader to boot them. You can manually configure additional operating systems if they are not detected automatically. See Configuring boot loader in Section 4.4, “Configuring software options” for more information.

Installing RHEL from an image on a local hard drive

Record: The hard drive and directory that holds the image.

Installing RHEL from a network location

If the network has to be configured manually, that is, DHCP is not used.

Record:

  • IP address
  • Netmask
  • Gateway IP address
  • Server IP addresses, if required

Contact your network administrator if you need assistance with networking requirements.

Installing RHEL on an iSCSI target

Record: The location of the iSCSI target. Depending on your network, you may need a CHAP user name and password, and a reverse CHAP user name and password.

Installing RHEL if the system is part of a domain

Verify that the domain name is supplied by the DHCP server. If it is not, enter the domain name during installation.

B.4. Disk and memory requirements

If several operating systems are installed, it is important that you verify that the allocated disk space is separate from the disk space required by Red Hat Enterprise Linux.

Note
  • For AMD64, Intel 64, and 64-bit ARM, at least two partitions (/ and swap) must be dedicated to Red Hat Enterprise Linux.
  • For IBM Power Systems servers, at least three partitions (/, swap, and a PReP boot partition) must be dedicated to Red Hat Enterprise Linux.

You must have a minimum of 10 GiB of available disk space. See Appendix C, Partitioning reference for more information.

To install Red Hat Enterprise Linux, you must have a minimum of 10 GiB of space in either unpartitioned disk space or in partitions that can be deleted. See Appendix C, Partitioning reference for more information.

Table B.1. Minimum RAM requirements

Installation typeRecommended minimum RAM

Local media installation (USB, DVD)

768 MiB

NFS network installation

768 MiB

HTTP, HTTPS or FTP network installation

1.5 GiB

Note

It is possible to complete the installation with less memory than the recommended minimum requirements. The exact requirements depend on your environment and installation path. It is recommended that you test various configurations to determine the minimum required RAM for your environment. Installing Red Hat Enterprise Linux using a Kickstart file has the same recommended minimum RAM requirements as a standard installation. However, additional RAM may be required if your Kickstart file includes commands that require additional memory, or write data to the RAM disk. See the Performing an advanced RHEL installation document for more information.

B.5. RAID requirements

It is important to understand how storage technologies are configured and how support for them may have changed between major versions of Red Hat Enterprise Linux.

Hardware RAID

Any RAID functions provided by the mainboard of your computer, or attached controller cards, need to be configured before you begin the installation process. Each active RAID array appears as one drive within Red Hat Enterprise Linux.

Software RAID

On systems with more than one hard drive, you can use the Red Hat Enterprise Linux installation program to operate several of the drives as a Linux software RAID array. With a software RAID array, RAID functions are controlled by the operating system rather than the dedicated hardware.

Note

When a pre-existing RAID array’s member devices are all unpartitioned disks/drives, the installation program treats the array as a disk and there is no method to remove the array.

USB Disks

You can connect and configure external USB storage after installation. Most devices are recognized by the kernel, but some devices may not be recognized. If it is not a requirement to configure these disks during installation, disconnect them to avoid potential problems.

NVDIMM devices

To use a Non-Volatile Dual In-line Memory Module (NVDIMM) device as storage, the following conditions must be satisfied:

  • Version of Red Hat Enterprise Linux is 7.6 or later.
  • The architecture of the system is Intel 64 or AMD64.
  • The device is configured to sector mode. Anaconda can reconfigure NVDIMM devices to this mode.
  • The device must be supported by the nd_pmem driver.

Booting from an NVDIMM device is possible under the following additional conditions:

  • The system uses UEFI.
  • The device must be supported by firmware available on the system, or by a UEFI driver. The UEFI driver may be loaded from an option ROM of the device itself.
  • The device must be made available under a namespace.

To take advantage of the high performance of NVDIMM devices during booting, place the /boot and /boot/efi directories on the device.

Note

The Execute-in-place (XIP) feature of NVDIMM devices is not supported during booting and the kernel is loaded into conventional memory.

Considerations for Intel BIOS RAID Sets

Red Hat Enterprise Linux uses mdraid for installing on Intel BIOS RAID sets. These sets are automatically detected during the boot process and their device node paths can change across several booting processes. For this reason, local modifications to the /etc/fstab, /etc/crypttab or other configuration files that refer to the devices by their device node paths may not work in Red Hat Enterprise Linux. It is recommended that you replace device node paths (such as /dev/sda) with file system labels or device UUIDs. You can find the file system labels and device UUIDs using the blkid command.