Craig Hesling

GPG Agent for SSH Authentication (Update)

https://gist.github.com/mcattarinussi/834fc4b641ff4572018d0c665e5a94d3

echo "use-agent" >> ~/.gnupg/gpg.conf
echo "enable-ssh-support" >> ~/.gnupg/gpg-agent.conf
echo "IdentityAgent /run/user/1000/gnupg/S.gpg-agent.ssh" >> ~/.ssh/config

# Run the following to figure out what your SSH "A" key's Keygrip is:
gpg --list-keys --with-keygrip

# Add your key's keygrip to the sshcontrol file
echo A55719832AF939C531BACFFABB2A47B52FFBBF43 >> ~/.gnupg/sshcontrol

# Once you add the key to the sshcontrol file, you should see a key available to ssh-add
ssh-add -l

From https://www.makeuseof.com/intel-u-vs-p-vs-h-laptop-cpus/, we have the following CPU suffixes/product-lines:

Intel’s description can be found https://www.intel.com/content/www/us/en/processors/processor-numbers.html

• https://wiki.archlinux.org/title/libvirt
• Use usermode session qemu://session instead of qemu://system.
  https://blog.wikichoon.com/2016/01/qemusystem-vs-qemusession.html
  https://jonaspfannschmidt.com/libvirt_session.html
• This post explains how to share the network bridge:
  https://mike42.me/blog/2019-08-how-to-use-the-qemu-bridge-helper-on-debian-10
  

Notes for 32/64 bit usage and conversion:

• https://nolongerset.com/32-bit-and-64-bit-access-side-by-side/

Tools:

• https://support.microsoft.com/en-us/office/compare-two-versions-of-a-database-database-compare-a969a77a-5251-4b59-84ea-74e12a135a05#__toc382559932

You can’t take normal full featured libvirt snapshots, since we are using UEFI.

• Chris does a pretty good job at Chris’s Wiki :: blog/linux/LibvirtUEFISnapshots.
• https://fabianlee.org/2021/01/10/kvm-creating-and-reverting-libvirt-external-snapshots/

Although Chris makes a good point about not using external snapshots, I prefer to have the visual reminder in virt-manager that a snapshot is available. I’m going to give external snapshots a try anyways. Here are the relevant commands:

virsh snapshot-list $domain

# Create snapshot
virsh snapshot-create-as $domain --name $snapshotname --disk-only

# Check that we are now using the new snapshot qcow2 file
virsh domblklist $domain

# If we navigate to where the qcow2 files are stored, we
# should see the original img file and a new file
# Alternate path: /var/lib/libvirt/images
pushd ~/.local/share/libvirt/images
ls -al
# Running the file command can reveal the backing file info
file *

# To delete a snapshot metadata
virsh snapshot-delete --metadata $thedomain $snapshotname

# Also note ~/.config/libvirt directory

Comparing the emulated SATA and VirtIO, the VirtIO disk comes out massively faster.

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It looks like IO speed might be CPU latency bound, since setting the virtual disk caching mode to unsafe doesn’t really improve the performance by much.

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Reference Performance of the underlying Samsung PM951 NVMe

The Microsoft Android RD client app seemed to be blocked fro install on certain Chromebooks, although it looks like this has been reversed. If it happens again, the next best RDP client is the Remmina, which can be installed through “Linux”/crostini.

# Statup Linux
sudo apt update
sudo apt install remmina
# Seacrh for remmina in ChromeOS search bar.