2024-03-09 Meeting

The Discussion:

We had a good discussion about various topics including:

  • How to troubleshoot a microphone using Jitsi on Firefox
  • TPM vs. Secure Boot
  • Check for presence of a Trusted Platform Module in Linux (dmesg | grep -i tpm)
  • Lynis and security recommendations
  • Pat recommended this page to help understanding LVM

The Presentation:

Carl provided a live demonstration about block devices and filesystems.  Using a virtual machine with a fresh installation of Linux Mint, he showed how to query and manage devices and filesystems on a Linux platform.  Here are the key commands that were demoed.

  • mount
    displays mounted devices including filesystems
  • df -h
    lists mounted filesystems
  • lsblk
    lists block devices
  • lsblk -e7
    ignores loop devices
  • lsblk -f
    includes filesystem information, if available
  • blkid
    gives more detailed information about devices
  • pvs, vgs, and lvs
    shows summary of LVM physical volumes, volume groups, and logical volumes
  • pvdisplay, vgdisplay, and lvdisplay
    shows details about physical volumes, volume groups, and logical volumes
  • lvcreate and mkfs.ext4
    creates and formats a new logical volume in a volume group
    lvcreate -L 6G -n home vgmint
    lvcreate -L 100%FREE -n tmp vgmint
    mkfs.ext4 /dev/vgmint/home
    mkfs.ext4 /dev/vgmint/tmp
  • mount
    mounts newly formatted logical volumes
    mkdir -p /home2
    mount /dev/vgmint/home /mnt/home2

  • pvcreate
    formats a new physical volume
    after using fdisk to create a partition of type 8E:
    pvcreate /dev/vdb1
    to use entire harddrive:
    pvcreate /dev/vdc 
  • vgextend
    adds one or more physical volumes to a volume group
    vgextend vgmint /dev/vdb1 /dev/vdc 
  • lvresize and resize2fs
    increases size of a logical volume and resizes filesystem
    lvresize -L 10G /dev/vgmint/home
    resize2fs -p /dev/vgmint/home 
  • pvmove, pvreduce, and pvremove
    removes device from LVM
    pvmove /dev/vdb1
    pvreduce vgmint /dev/vdb1

    pvremove /dev/vdb1 
  • lvremove
    removes a logical volume from a volume group
    lvremove /dev/vgmint/tmp