I upgraded a Mid 2012 MBP to latest macOS High Sierra today. While this is an older model the process went smoothly. The unit was running El Capitan (10.11). It should be noted that the hardware had previously been updated. It was running:
The SSD drive is a solid investment anyone should make on older Apple hardware. Not only is it a performance boost it also sped up the upgrade process significantly.
The first step in any upgrade is to make sure you have a backup. Whether that is a disk clone, time machine or other third party application (like BackBlaze)
My preferred upgrade method is to use create a bootable external drive (USB or SSD). This is easily accomplished using terminal:
sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ macOS\ High\ Sierra.app
This example will write the files to a USB drive titled “Untitled”. Adjust to match your volume name. Macworld has a great article on this with alternate methods. If something goes wrong you can use this boot device to either start again or do a time machine restore.
Once the boot volume is ready restart your Mac and hold down the Option key at start to get the boot menu. Choose the Install macOS High Sierra volume to boot from. After a short while, USB is a bit slow, this will bring up a menu where you can choose a number of options. Pick upgrade macOS and the process will start.
It took 45 minutes to upgrade this older hardware. It would take much longer on an old Mac without a SSD drive, possibly hours.
Everything appeared to work right from first login. I already knew telnet had been removed so I simple restored from a time machine backup to /usr/local/bin.
This Mac has Microsoft Office 2011 and early testing shows it works fine. Microsoft recently stated it is not tested and may not function correctly. I’ll update this with any specific issues if they arise.
So far only one major issue with a second monitor. The computer would not recognize a second monitor was attached through a mini-dvi to VGA adapter. Shutting down the computer and starting with the adapter attached seem to correct the problem for the moment.