Rsync: sparse files, COW target and want more progress indicator

[sampsonf (Sampson Fung)]

Continuing the discussion from How to judge if a backup process is perfect?:

From the above discussion, I learnt that rsync is the tool for me to do file level backup.

As advised, my follow up questions can be asked in a separate thread, so I am linking and quoting here:

@SampsonF

After this round of transfer of 2.7TB of files, I will stick with rsync for file level transfers from now on.

A few questions:

• how to prevent spase qcow2 files become fully allocated after rsync?

• when the file is not exist in target

• when the target exist in target but needs update

• how to make rsync work nicely with COW btrfs filesystem? So far, I googled and used this:
  rsync --inplace --info=progress2 --no-whole-file -a source/ btrfs/

I so far only run rsync interactively, I would like as much progress indication as possible, like which file is being compared, which file is being transmitted, how much changed of each file, etc. With --info=progress2, I only got this one line staus:
0 0% 0.00kB/s 0:00:00 (xfr#0, ir-chk=2025/18024)

What parameters can provide such progress indications while rysnc is running?

[sampsonf (Sampson Fung)]

The first run is the “tar” process as outline in the origination thread.

The second run is
# sudo rsync --inplace --info=progress2 --no-whole-file -a /mnt/ntfs/ /mnt/btrfs/
(I do not save the final progress bar outout, the I remember xfr#8 , and total file is 1.4M)

# sudo rsync --checksum --inplace --info=progress2 --no-whole-file -a  /mnt/ntfs/  /mnt/btrfs/
                  0   0%    0.00kB/s    0:00:00 (xfr#0, to-chk=0/1447024)  

Question:
Provided the first two runs and done, is it normal to have the 4 leading zeros in the final progress bar?

Observation:

• during this third run, I expect the dedicated /mnt/btrfs drive will be read constantly. But it is not. Majority of time there is no activity to the btrfs drive. (its enclosure has activities LEDs.)