Hi – I have been having some issues on my late 2013 Imac since upgrading to Catalina. A lot of library messages in the logs for example. Sometimes if I go to shutdown I get a black screen for a while then it reboots, other times it’s fine. Sometimes when emptying the bin it just sits there on the screen and other odd behaviours. Have run Malwarebytes and nothing untoward there.
It’s got very frustrating so I thought I might try and download Catalina again and refresh it. Using the Recovery, Installed OS option, does this download a new copy of the OS to the Macintosh HD partition while keeping Macintosh HD-Data partition separate? I have a Time Machine backup and also other separate copies of the three users Photos library from the iMac but wanted to know if I can re-install the OS without specifically doing anything else to keep my data. Sorry if this is basic question but in Mac terms I am not that experienced.
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Gregory
It is normal to have your logs filled with all sorts of things. It doesn't necessarily mean there is a problem. Most people never even look at their logs over the entire life of their Macs. So I wouldn't worry too much about that. A delay during a shutdown isn't usually a problem either. How often do you shut down? There's rarely a need to do so. See: https://macmost.com/e-1571
I wouldn't try a reinstall of macOS over this. It most likely won't make a difference and it is a big operation. I don't see it as a solution. Maybe 20 years ago this was a good technique, but not today. I'd recommend things like SMC and NVRAM resets, rebooting into safe mode and then back normally again -- except that if log files and an occasional delay when shutting down are your only symptoms, I don't see much of a problem to fix.
For others with serious issues, it isn't necessarily a good option either. Chances are that it is something you have installed, like an app or some data corruption that is causing the issue. Reinstalling macOS won't fix that at all since the problem is in the user side, not the system side.
If you do reinstall the OS it shouldn't overwrite any of your user files unless you choose to erase your drive. So be careful when you do it and pay attention to everything. Plus, you have your backups just in case.