Mac mini, iMac (2017): Data transfer, display use

jmdchan wrote:

Sonoma 14; I'm aware of the issue that my Mac will not accept Sonoma 14. That said I need to know how I still use my iMac (2017 mfg) with a Mac Mini?

If I integrate a Mac Mini will I lose all of data and apps I use or will these be transferred to the Mac Mini?

You won't (shouldn't)lose your data. However, you may not be able to use the apps that are installed on the iMac, depending on which macOS version it is running. If upgrading from 10.14 Mojave or earlier, your older 32-bit apps & drivers won’t work in Catalina or newer. They must also be updated or replaced.  Use the free utility Go64 app from St. Claire Software to check your current iMac apps.

As always, backup your iMac before you migrate.

Back up your Mac with Time Machine - Apple Support

If Integrate the Mac Mini will I be able to use my iMac's 21.5" display?

No. Once upon a time there was a method for this, but the tech in software and hardware is dead and buried.

Expect to budget for a dedicated monitor for your Mac mini, starting at about $150 or so.

My iMac has 1.03 TB capacity and I presently use 286 GB.

Avoid migration problems and future proof your Mac mini by getting one with plenty of storage. In your case 500 GB minimum, and your best option, imho, would be a 1 TB drive if you hope to use the mini for 8-10 years as you have apparently done with the iMac. Whatever you do, do not buy the 250 GB drive option. That's not enough storage and is problematic for so many users.

You can not integrate those Mac’s or use the iMac as the primary display for the Mac mini.

If you get or have a new Mac mini:

1) You need an external display to use with the Mac mini.

Connect a display to Mac mini - Apple Support

2) Then you need to migrate your data to the Mac mini.

Transfer to a new Mac with Migration Assistant - Apple Support

Third-party solutions such as Luna Display or Duet Display are performance limited and  suited only for uses where there will be little motion and where latency is not an issue, such as for application tool palettes. You will still need a proper monitor to set up either of those options.

❝Like any product, Luna Display does have limitations and it’s not recommended for high-motion content. For example, I wouldn’t recommend using Luna Display for gaming or video editing.❞ - Luna website (Their emphasis, not mine.)

Full disclosure:

That setup (target display mode) is no longer supported by Apple. The old iMac cannot be used as a monitor for any of the newest Macs and Target Display mode is no longer a feature of macOS, having been deprecated years ago. Apple killed target display mode hardware when the first Retina Macs were released in 2014 and the feature died in software with the release of macOS 11 Big Sur.

Please see: Use your iMac as a display with target display mode - Apple Support

Per the link above:

• Only certain older iMac models, introduced between 2009 and mid-2014, could be used as target displays and required either a Thunderbolt or Mini DisplayPort cable.
• The intended target iMac must be running macOS 10.13 High Sierra or earlier; it does not work with macOS 10.14 Mojave or later, or with Boot Camp and Windows.
• Retina display iMacs won’t work as target displays.
• In all cases the source Mac that you're connecting FROM must have been introduced in 2019 or earlier and have macOS 10.15 Catalina or earlier installed.

Please also see: Using an iMac As A Monitor (Thank you, John Galt)

Exceptions to the TDM Rules:

https://discussions.apple.com/thread/256051293?sortBy=oldest_first

Luna Display is not the same as having an external display connected to the M4 Mac mini.

You will need an External Display or an HDMI TV connected to the Mac mini to do the initial setup.

Plus you will most likely suffer from Latency and Connection issues while using that setup.

It doesn’t make any sense to use Luna Display to reuse a 21.5” 1920x1080 pixel iMac screen.

It might make sense to use Luna Display to reuse a 21.5” Retina 4K iMsc’s screen as a second screen, but you’d still need at least one real hardware monitor, and you’d need to live with any lag/latency issues.

So which 21.5” iMac screen do you have?