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Precision 5510 - Gentoo GNU/Linux

October 12, 2019 — Jesse Harris

This documents all configurations, apps and tweaks to get a nicely working Linux machine.


Installation

Partition

The system was built with an existing Windows EFI partition table but this weekend I converted it over to a luks/dmcrypt partition scheme. Thus the table was created is as follows:

  1. 200Mb ESP volume
  2. 477.8G Linux filesystem

The Linux filesystem is an aes-xts-plain64 with a 512 key size.

        cryptsetup luksFormat /dev/nvme0n1p6 -c aes-xts-plain64 -s 512

After the encrypted volume is created, and opened, lvm was used to create a 444Gb partition for root and the remaining 32Gb for swap/resume. The root volume then formatted with btrfs.

        mkfs.btrfs /dev/mapper/lvm-root

Mounting the btrfs root subvolume in the Gentoo Live install:

        mkdir /mnt/btrfs
        mount /dev/mapper/lvm-root /mnt/btrfs

Create 2 subvolumes in the / root and mount @root

        btrfs subvolume create /mnt/btrfs/\@root
        btrfs subvolume create /mnt/btrfs/\@home

        mount /dev/mapper/lvm-root /mnt/gentoo -o subvol=@root

Stage3

The original stage3 tarball was stage3-amd64-systemd-20190823.tar.bz2
systemd was chosen so that I'm using the same init system that I need to support for my day job.

After stage 3 is extracted, mount the home subvolume and boot volume:

        mount /dev/mapper/lvm-root /mnt/gentoo/home -o subvol=@home
        mount /dev/nvme0n1p1 /mnt/gentoo/boot

Chroot in as per the Gentoo handbook

Portage

Initial portage make.conf setup to get going should include the following:

        COMMON_FLAGS="-march=skylake -O2 -pipe"
        VIDEO_CARDS="intel i965"
        MAKEOPTS="-j9 -l8"
        GENTOO_MIRRORS="http://ftp.swin.edu.au/gentoo"
        EMERGE_DEFAULT_OPTS="--jobs=8 --load-average=8"
        FEATURES="${FEATURES} parallel-fetch"

More settings to be discussed in Make.conf section later. This is all that is relevant for the initial install.

Kernel

Kernel config can be found on my kernel-configs github repo Make it with -j8 for all cores and after installed, edit /etc/default/grub:

        GRUB_CMDLINE_LINUX="dobtrfs rootfstype=btrfs"

Use genkernel-next to build an initramfs and install grub

        genkernel initramfs
        grub-install /dev/nvme0n1

Applications

First app in vim, as it is not in Gentoo base, other handy apps for getting the system up and running:

  • app-editors/vim
  • app-admin/sudo
  • app-portage/eix
  • app-portage/gentoolkit
  • dev-vcs/git
  • sys-apps/usbutils
  • sys-fs/btrfsprogs
  • sys-boot/os-prober
  • sys-kernel/genkernel

Note Genkernel pulls in sys-kernel/linux-firmware which has the binary blobs required to get the wifi chip working on the Precision 5510.

World build

As per the Handbook, build the world, install the kernel, grub and reboot. But! Don't forget to set the root password

First setup

After first boot systemd has everything you need to get connected to the network to get everything going. Create a file in /etc/systemd/network to setup dhcp on eth0. Enable systemd-networkd to get going until networkmanager later.

Administration

Setup sudo for quicker elevation:

        vim /etc/sudoers
        
        %wheel ALL=(ALL) NOPASSWD: ALL

Useful groups

wheel : Allows to su to root, or use sudo
plugdev : Allows to connect to wifi as regular user and other hardware stuff
portage : Can write into portage distfiles for testing and making ebuilds

Sleep and hibernate

Swap file is big enough to hold most of the RAM. Grub config is updated to specify the swap partition UUID as the resume parameter

        GRUB_CMDLINE_LINUX="dobtrfs rootfstype=btrfs resume=UUID=9a900eaa-0312-4796-93f8-da3245add9d4"

Suspend then hibernate delay is set to 4 hours:

        vim /etc/systemd/sleep.conf

        [Sleep]
        HibernateDelaySec=240min

Lidswitch is set to suspend then hibernate

        vim /etc/systemd/logind.conf

        [Login]
        HandleLidSwitch=suspend-then-hibernate
        HandleLidSwitchDocked=ignore

Xorg and Gnome

use flags for gnome added to make.conf

        USE="gtk bluetooth gnome -qt gdm samba acl vim readline"
        L10N="en" # for dictionary in evolution

emerge gnome-base/gnome and the following apps

  • gnome-base/gnome-vfs # For smb connections in nautilus
  • gnome-extra/evolution-ews # Connect evolution to exchange online
  • x11-terms/kitty # terminal with ligature font support
  • www-client/firefox-bin

Packages for work

  • net-vpn/networkmanager-openconnect # vpn in networkmanager for work
  • net-misc/freerdp # Rdp to servers for work
  • net-misc/icaclient # Citrix client for work

Extending Gentoo

Apart from emerge, I'm making use of other package managers on Gentoo to complete the environment.

Install layman

        emerge -a layman
        layman -L
        layman -a snapd
        layman -a flatpak
        layman -o http://jesseharrisit.com/overlay.xml -f -a gentoo-zigford
        emerge -a app-emulation/snapd
        emerge -a app-emulation/flatpak

        

snapd packages

        snap install chromium
        snap install teams-for-linux
        snap install p3xonenote
        snap install caprine

KVM - Qemu

For virtualization, I primarily want to interface with VM's using gnome-boxes, however as it lacks the sophistication for complex VM's, I also install virt-manager.

Use flags for virtualization:

        app-emulation/libvirt apparmor virt-network
        app-emulation/qemu doc usbredir smartcard spice
        app-emulation/spice smartcard
        net-dns/dnsmasq script
        net-misc/spice-gtk smartcard usbredir vala

Kernel settings to enable networking in the kernel mentioned earlier. qemu settings required for efi virtual machine

        vim /etc/libvirt/qemu.conf
        security = "none"
        nvram = [
            "/usr/share/edk2-ovmf/OVMF_CODE.fd:/usr/share/edk2-ovmf/OVMF_VARS.fd"
        ]

For a vm in boxes to run efi:

        cp /etc/libvirt/qemu.conf ~/.config/libvirt

Group memberships:

        usermod -G kvm,libvirt -a username

Tweaks to apparmor

        sed -ie 's/#include <local/include <local/' usr.sbin.dnsmasq
        vim local/usr.sbin.dnsmasq
        
        capability mknod,
        /usr/libexec/libvirt_leaseshelper rix,
        /var/lib/libvirt/dnsmasq/*.status* rw,
        /run/leaseshelper.pid rwk,
        
        vim usr.sbin.libvirt
        
        capability sys_rawio,

Set libvirt images directory to no copy on write

        chattr +C /var/lib/libvirt/images

Backups

Thanks to the power of btrfs, backups are facilitated easily by snapshots. Currently I have a systemd timer set to fire every hour. It fires a script which does the following:

  1. Mount the root btrfs volume to /mnt/btrfs (this houses 2 subvols)

  2. Snapshot each subvol into /mnt/btrfs/snapshots/subvolname-yyyy-MM-dd-hh:mm:ss

  3. Prune any snapshots that are not any of the following:

    • in the last 24 hours
    • daily in the last month
    • monthly in the last year
  4. If a designated backup drive is attached, transfer all snapshots

  5. Delete all bar the last 2 transfered per subvolume

Finally, if the drive is not attached, when it does become available the script is invoked with a parameter to just catch up on the snapshots.

The script can be found on github and the systemd timer and service look like this:

snapshot.service

        [Unit]
        Description=Take a BTRFS Snapshot of all the volumes

        [Service]
        Type=simple
        ExecStart=/usr/local/bin/snapshot

snapshot.timer

        [Unit]
        Description=Timer file for snapshot unit. Snapshots hourly and continually prunes

        [Timer]
        OnCalendar=*-*-* *:00:00
        Persistent=true

        [Install]
        WantedBy=timers.target

backup-snapshots.service

        [Unit]
        Description=Backup snapshots when backup drive is attached
        Requires=run-media-harrisj-7cb22d51\x2db8a7\x2d45ee\x2db1a3\x2d2f3db51c931f.mount
        After=run-media-harrisj-7cb22d51\x2db8a7\x2d45ee\x2db1a3\x2d2f3db51c931f.mount

        [Service]
        ExecStart=/usr/local/bin/snapshot -b

        [Install]
        WantedBy=run-media-harrisj-7cb22d51\x2db8a7\x2d45ee\x2db1a3\x2d2f3db51c931f.mount

Tags: Gentoo, btrfs, linux