Yocto Installer

•  TODO

The compilation and installation of the Yocto version of SEAPATH is entirely described on the GitHub repository seapath/yocto-bsp.

Debian Installer

To install the cluster, you need to generate an ISO, based on Debian 11, for each host with this repository here.

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See the below section for more details on the configuration file.

Configuration

In the configuration file, you must define these variables:

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However, all host will be with the same IP address.

Prerequisite

When the host is installed, the ansible/playbooks/cluster_setup_prerequisdebian.yaml need to launch to finish the installation.

The inventory must define these variables to run the playbook:

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apply_network_config: Boolean to apply the network configuration

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IP

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cpumachinesnort: Range of allowed CPUs for no RT machines

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cpumachines: Range of allowed CPUs for machines (RT and no RT)

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cpumachinesrt: Range of allowed CPUs for RT machines

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cpuovs: Range of allowed CPUs for OpenVSwitch

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cpusystem: Range of allowed CPUs for the system

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cpuuser: Range of allowed CPUs for the user

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main_disk: Main disk device to observe his temperature

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workqueuemask: The negation of the irqmask (= ~irqmask)

In this part, the playbook define the scheduling and the prioritization (see the section).

Hardening

The ansible/playbooks/cluster_setup_hardening_debian.yaml playbook enables system hardening and the ansible/playbooks/cluster_setup_unhardening_debian.yaml playbook disables it.

The hardened elements are:

• the kernel with the parameters of the command line (see below section), the sysfs and modules;
• the GRUB;
• the systemd services;
• adding of bash profiles;
• SSH server;
• adding of sudo rules;
• the shadow password suite configuration;
• the secure tty;
• the audit daemon.

Kernel

The project uses a real-time kernel, the Linux kernel with the PREEMPT_RT patch. So, he needs to have some parameters as:

• cpufreq.default_governor=performance: Use the performance governor by default (more details here).
• hugepagesz=1G: Uses 1 giga-bytes for HugeTLB pages (more details here).
• intel_pstate=disable: Disables the intel_pstate as the default scaling driver for supported processors (more details here).
• isolcpus=nohz,domain,managed_irq: nohz to disable the tick when a single task runs; domain to isolate from the general SMP balancing and scheduling algorithms; managed_irq to isolate from being targeted by managed. See the Scheduling and priorization section.
• no_debug_object: Disables object debugging.
• nosoftlockup: Disable the soft-lockup detector (more details here).
• processors.max_cstate=1 and intel_idle.max_cstate=1: Discards of all the idle states deeper than idle state 1, for the acpi_idle and intel_idle drivers, respectively (more details here).
• rcu_nocbs: See the Scheduling and priorization section.
• rcu_nocb_poll: Make the kthreads poll for callbacks.
• rcutree.kthread_prio=10: Set the SCHED_FIFO priority of the RCU per-CPU kthreads.
• skew_tick=1: Helps to smooth jitter on systems with latency-sensitive applications running.
• tsc=reliable: Disables clocksource verification at runtime, as well as the stability checks done at bootup.

In the hardening system, the kernel has these parameters:

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More details on the kernel's parameters here.

Disks

The disk is composed:

1. (If the installation is in UEFI) EFI partition in /boot/efi with VFAT filesystem (512 MB).
2. Boot partition in /boot with ext4 filesystem (500 B).
3. Main partition with LVM configuration (30 GB). This partition is divided into 3 parts:
   1. Root partition in / with ext4 filesystem (7 GB).
   2. Log partition in /var/log with ext4 filesystem (1 GB).
   3. Swap partition (500 B).

This can be changed in the build_debian_iso/srv_fai_config/disk_config/ directory. There is always 2 versions (one in Legacy BIOS and an other in UEFI mode with the suffix "_EFI").

Virtual cluster

On the host, you must set these sysctl settings:

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You must define 3 network interfaces on each host of your cluster.

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