2.7. Reflection Checkpoint

Confirm you can answer these from understanding before moving to Phase 3:

Storage Stack:

• In order, name the four layers of the Linux storage stack from physical disk to mounted path.
• What is the difference between fdisk and gdisk? When would you use each?
• After lvextend -L +20G /dev/vg/lv_data, what additional step is required for an ext4 filesystem? For XFS?
• Why must NFS/CIFS entries in /etc/fstab include the _netdev option?

Networking:

• What happens to an ip route add command after a reboot? How do you make it persistent?
• What does ss -tulnp show? What does each flag mean?
• What is the difference between /etc/hosts, /etc/resolv.conf, and /etc/nsswitch.conf?

Shell and Tools:

• What is the difference between > and >> redirection?
• Why does cmd 2>&1 > file produce a different result than cmd > file 2>&1?
• What is the difference between rsync -av /source/ /dest/ and rsync -av /source /dest/?

Virtualization:

• What is the relationship between KVM and QEMU?
• What does virsh destroy do? Does it delete the VM's data?
• What network type gives a VM an IP address visible on the same subnet as the host?