Using Linux Mint 19.1 bootable USB
By default fsarchiver uses zstd compression
Earlier when I used the following two commands, each command individually took maximum 5 minutes to complete.
fsarchiver -v -j6 savefs /backup/backup-fsa/backup01.fsa /dev/sda2 fsarchiver -v -j6 restfs /backup/backup-fsa/backup01.fsa id=0,dest=/dev/sda2
Now, each command takes couple of hours to complete. I noticed that mainly one core and 20% of my ram is used during the process.
Just to make sure,
dd works fine. It makes the image fast. So, I do not think there is a hardware bottleneck. I think I am doing something wrong with the command.