Always put your root partition separate from the storage (aka data) partitions. root partition should be only for system files and nothing more! Keeping this simple rule you may easily change your operating system (or clean install or clean upgrade) without deleting the user’s data thus preserving the old storage partitions.
Our storage has 2 storage partitions, which means they hosts only data and no system files and there are separate partitions for Linux booting (grub2) and system files (root partition). Here is the partitions layout:
Of course, when there are partitions above 2T the GPT is mandatory.
You can skip the software RAID1 setup if you use only one controller or you have system partitions only in one disk (virtual drive and so on). Here we have two hardware controllers, which we want to use both for the system partitions.
4 RAID1 devices:
EFI partition (/boot/efi)
boot parition (/boot)
root partition (/)
The best practice is have total between 30G and 50G for the 4 partitions (in fact, boot partition could be skipped). Have in mind most modern Linux distributions cannot be installed on less than 10G~20G and for optimal results just separate between 30G and 50G for 4 partitions above (or 3 if you choose to skip the boot one).
Upgrade to CentOS 8 with clean install over our old CentOS 7 system partitions preserving the big data partitions.
Couple of things before start:
UEFI installation will be selected. So boot in UEFI mode.
IPMI KVM is used to install the new Linux distribution – CentOS 8
This article shows what files to add if you want to add a bonding interface under CentOS 8 without invoking the Network manager command utility.
Our goal is to use one boding group with the name bond0 in LACP (aka 802.3ad) mode (but it could be any of the other types) with two networks 10Gbps interfaces. The setup resented here uses NetworkManager, which handles the loading of bonding module properly.
In fact, the network-scripts are now deprecated and they are missing from the system (but they still exist in the additional package – “network-scripts”, how knows till when? do not rely on them!).
The configuration files are with the same syntax as under CentOS 7, but this time the network manager parses them. The ifup and ifdown still exist and they just call the Network manager when executed (unless the “network-scripts” package is installed). If you need to enable bonding without any configuration files (for emergency situations) you may still use – How to enable Linux bonding without ifenslave
What do you need:
Ensure you have installed: “iputils” and “NetworkManager” packages
This article is for those of you who do not want to install a whole new operating system only to discover some technical details about the default installation like disk layout, packages included, software versions and so on. Here we are going to review in several sections what is like to have a default installation of CentOS 8.0.
Despite the kernel is 4.18 it detects successfully the new RYZEN/Threadripper AMD and the system is stable (we booted in UEFI mode).
The CentOS 8.0 (8.0.1950) you can have
linux kernel – 4.18.0 (4.18.0-80.7.1.el8_0.x86_64)
Graphical User Interface
Xorg X server – 1.20.3
GNOME (the GUI) – 3.28.2
K Desktop Environment – NO, it’s depricated and not included in the release.
Minimal net install is useful when a dedicated server is installed from a IPMI KVM or Dell iDRAC, HP iLO, IBM IMM or where the initial client side download of files need to be minimal.
For amd64 CentOS 8 BaseOS the net install bootable media is located here (now the current latest release is 8.0.1950, but you can check the last directory with 8. for the time you follow this howto):