Backing Up Hardisk to External HD with Catalina?

You can close system preferences with impunity. The first backup with TM will take ages. A second backup will take a shorter time, but still lengthy. It always seems to need a second large bite! After that it will back up only the incremental changes.

All copy routines, and TM is no exception, get indigestion with myriads of tiny little files. The first TM backup contains more of those than you can shake a stick at. When it hits a batch of large files it will race ahead.

Continue to use your machine as normal. TM is designed to handle real life users. It will incorporate any edits, new files, etc, into subsequent TM backups.

TM also lets you return in time to earlier versions of your files. Obviously it has to have backed them up first!

It is pretty much a fire and forget solution.

I view the TM backup as important enough to have invested in RAID storage so that I have one copy protected even in the event of the rare but inevitable backup drive failure. I had one fail recently after 5 years continuous use

Time Machine is your friend, the more so if you do not wish for a detailed and technical solution. There is no good reason not to use it. It works well and dependably, requiring no technical knowledge. Back up your Mac with Time Machine - Apple Support is valuable reading.

Note that Time Machine will correct the formatting on any USB (etc) drive you choose and thereby erase any data already upon it

Lanny wrote:

If your LaCie HD is mechanical, it will work noticeably slower with the APFS format. However, CCC requires the use of APFS if you want the clone to be bootable.

Interestingly I keep my Photos library on a G Technology 4TB spinning disk. It became faster after formatting it to APFS. Apple Support suggested it while diagnosing a Photo problem. I don't want to digress too far in this thread, though.

I think what we are showing arore is that TM and CCC can work in harmony, each doing its own job. However the original post states that the LaCie HD is formatted to APFS and still doesn't work correctly

I'm not 100% sure what I'm seeing? The highlighted drive seems to be your main internal drive, and fees normal. Is the external drive the backup drive upon which your TM backup sits? If so that does not appear correct.

Please can we see a screenshot of the Time Machine pane of System Preferences as well? This one is mine

I'm very much interested in the area I've highlighted in red. It ought to show both the items I've underlined. You shook also have had a message saying that the "First Backup" had finished as a pop out box

(I replied before your second post with multiple screenshots, but my request for the TN preferences pane still stands. Your internal disk structure feels normal)

I back up to a NAS, so my TM drive mounts and unmounts as TM requires it. I imagine, but do not know, that an external drive is handled in a similar way for the TM .backupbundle, so you will only see it mounted when TM is backing up to it. I am sure others will correct me here with their broader experience.

You can also open the Terminal app and enter the command (with your backup drive plugged in)

tmutil listbackups

It will provide a full list of all the completed backups taken.

The key with Time Machine is not to try to second guess it. Sometimes it takes a long time. Other times it whisks through the tasks. It takes care of all the background headaches. It compresses backups when it knows it needs to. It has restart points for continuing backups after machine oddities.

I've used it happily on a NAS for years. There have been glitches between the NAS and the Mac, but TM has worked steadfastly even when the NAS vendor didn't support TM and I had to use a nasty kluge!

One hint: If you have external drives that you wish to have included in the backup, AFTER the first backup has finished (doing it now will interrupt it and annoy you, but cause no actual backup damage) go into the Options area in System Preferences>Time Machine and check the exclusion list with the external drive you wish to back up plugged in. You can remove it from the exclusion list.

Note that ejecting an external disk while the backup is running will abort that particular backup. That's reasonable, when you think about it. It cannot back up what is not there!

I haven't the luxury of a large internal drive, so I keep my (huge) Photos library on an external drive. By default external drives are excluded. So I removed it for the exclusion list

By the way I suspect you enjoy full peace of mind. TM is wonderfully reliable. Even so you may choose to take a full disk snapshot whenever you wish using CCC. I recommend storing that in a separate location from your computer. Obviously that snapshot disk ought to be excluded from the TM backup!

TM seems to have the facility to sort sleeping out. Screensavers are unimportant to it. It truly is fire and forget, and I understand all your questions and concerns

If you are deeply curious, and I suspect you might be, you can issue the following command in Terminal to try to look under the hood. Just copy and paste it verbatim:

printf '\e[3J' && log show --predicate 'subsystem == "com.apple.TimeMachine"' --info --last 24h | grep -F 'eMac' | grep -Fv 'etat' | awk -F']' '{print substr($0,1,19), $NF}'

I was given this command by another user, and I have learnt over time to interpret most of what it tells me. I can't alter a thing TM does, but I'm geek enough to be fascinated by pretty tech things!

Lanny wrote:

See: https://bombich.com/blog/2019/09/12/analysis-apfs-enumeration-performance-on-rotational-hard-drives

Interesting. His tests are empirical, mine is anecdotal I gained about 5 minutes in 30 against a not APFS rsync copy of a Photos library. But I think we may be discussing the number of angels who can dance on the head of a pin.