macOS – A changelog by Daniel Mettler

July 29, 2024

How to determine/find out whether your Mac/macOS is in Safe Mode?

In the Apple menu, click on “About This Mac”
Then click on the “More info…” button
Click on the “System Report…” button
In the appearing System Report window, click on the “Software” menu item in the left pane
In the right pane, look for “Boot Mode:”. It should be “Safe”.

(I recently noticed that it’s quite difficult to distinguish whether your Mac has really been booted in “Safe Mode”, as visually, there doesn’t seem to be much of difference anymore to how the desktop looks in regular mode)

And BTW, to boot a Mac with Apple Silicon in Safe Mode:

Shut your Mac/macOS down
To boot it again, press the power button and hold it
Select the volume to boot (i.e. click on the volume icon)
Hit and hold the shift key
Click on the appearing text (“Continue in Safe Mode” or so) below the volume icon

April 2, 2023April 1, 2023

macOS Ventura: Fix the “Operation not permitted” error in Terminal

The “Operation not permitted” error message is caused by one of the typical ~~annoyances~~features in macOS, namely the Terminal app lacking “full disk access” by default (and by design).

This conclusion unfortunately isn’t obvious, as when encountering the above error message, one would typically first check the ownerships and permissions of the directory/file/symlink “causing” the error, then perhaps the ACL / extended attributes, then whether the resource might still be locked by another process accessing it, and last but not least, one would remember macOS’s SIP (System Integrity Protection) and even consider booting into recovery mode. But none of that is actually required. The solution is:

In the macOS “System Settings”, go to “Privacy & Security”
Then click on “Full Disk Access” and enable it for “Terminal” (slider turns blue)
Open a new Terminal window/session

Irritatingly, upgrading to macOS Ventura apparently resets the Terminal app’s security privileges.

Example:

I wanted to remove and recreate a symlink, so that “MobileSync” (where macOS stores backups of iOS devices like iPhones, iPads) isn’t just a regular, local directory, but a symlink pointing to a directory on a mounted NAS share. Advantage: Backups of iOS devices don’t use up valuable (and expensive) SSD storage space on your MacBook Air/Pro, but use cheap NAS storage instead (further, you don’t create duplicate backups on each of your Macs). Here’s where the MobileSync symlink is located and where it points to, in my case (you can create it using ‘ln -s /Volumes/backups_ios/MobileSync .‘, my share is named ‘backup_ios‘)

mymac ~/Library/Application Support $ ls -lad ~/Library/Application\ Support/MobileSync
lrwxr-xr-x 1 myuser staff 31 Apr  1 00:47 '/Users/myuser/Library/Application Support/MobileSync' -> /Volumes/backups_ios/MobileSync

Even as root, I first couldn’t remove the symlink I created some time back before the upgrade to Ventura. Which is even the more puzzling considering this all happens in a regular user’s home directory.

May 1, 2020May 9, 2020

New Apple Magic Keyboard with Numeric Keypad is surprisingly good, even excellent!

Recently, I’ve managed to render my beloved old Apple Keyboard (full-size, with numeric keypad) useless – accidentally pouring half a glass of tap water over it was sufficient, unfortunately (due to the mineral ions in the tap water; distilled water wouldn’t have conducted electricity and thus wouldn’t have shorted circuits; on the other hand, drinking distilled water would probably shorten your life, so please don’t consider doing this).

Luckily, I could temporarily use a similarly old, compact Apple Bluetooth keyboard instead. As I really wouldn’t recommend that keyboard for everyday work though (poor, bubbly typing experience, odd placement of keys requiring weird function key combinations, no numeric keypad), I had to order a full-size keyboard as a replacement again, so I ordered one of the new Apple Magic Keyboards with a Numeric Keypad (in Space Gray and I really like that, but the colour doesn’t matter in regard to the typing experience):

https://www.apple.com/ch-de/shop/product/MRMH2SM/A/magic-keyboard-mit-ziffernblock-schweiz-space-grau

(above is the Swiss German version, US version: https://www.apple.com/shop/product/MRMH2LL/A/magic-keyboard-with-numeric-keypad-us-english-space-gray)

I first thought that the even smaller lift of the keys (luckily with scissor and not butterfly switches) of this new keyboard would be very disturbing and that I’d have a hard time getting accustomed to it.

To my big surprise however I got accustomed to this new typing experience within a couple of hours already and now, after about 3 weeks of using it, I can confidently say: I love this new Apple Magic Keyboard with Numeric Keypad even much more than my previous, old Apple Keyboard with Numeric Keypad and wouldn’t want to switch back anymore.

Typing with it feels so immediate, so quick and so “raw” and “crunchy”, it’s literally almost addictive. I can type considerably faster with it than with the previous keyboard, let alone any regular IBM-type keyboards (although I like those too, for their build-quality, for the interesting history and stories behind them, for their customizability and standardization, for the bustling keyboard enthusiast scene around it). Further, typing for a prolonged time feels much less tiring for the fingers, hands and forearms.

It feels as if you had to work with a wobbly tool for quite some time, then all of a sudden, get a very precise and exact instrument, like e.g. skiing with racing skis vs. with allround skis. It’s pure joy!

The difference is difficult to describe, so I would recommend you rather go experience it yourself and judge for yourself. For me, it’s my most favourite keyboard so far.

I’m even thinking of getting one for the Windows workstation at work too, it’s that good.

March 5, 2019March 5, 2019

macOS: How to remove stale/redundant entries from the “open with” context menu

To regenerate the “open with” context menu in macOS (and reopen Finder windows), execute the following two commands in Terminal:

$ /System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -kill -r -domain local -domain system -domain user
$ killall Finder

March 3, 2019March 3, 2019

IPMI Serial over LAN (SOL)

A nice summary by Werner Fischer (Thomas-Krenn) about how to enable and use Serial over LAN, particularly for Linux boxes:

IPMI Serial over LAN (SOL)

(In German, but you can easily translate it using your favourite online translation tool, e.g. deepl.com or Google Translate)

December 5, 2018

PDF Squeezer for macOS

If you’ve ever looked for a macOS tool that can compress PDFs, you’ve probably come across a list of dozens of apps in the Mac App Store for exactly that purpose. The problem: Most of them seem to be really old, incomplete, buggy or hardly working anymore.

One tool I can recommend (I bought it, use it almost daily and like it): PDF Squeezer (5.99 USD) (Home page)

Unlike the barely usable PDF compression feature in Apple’s Preview app (in the macOS file previewer, choose “Export…”, then “Quartz Filter: Reduce File Size”), PDF Squeezer manages to reduce a PDF file’s size by about 60-90% while retaining the original file’s legibility and good quality.

P.S. Another useful (free) tool from the same publisher, the PDF Print Service Creator, can be downloaded for free and allows to customize macOS’s print dialog in order to send any printable document directly to any of the apps that are capable of opening PDFs.

November 12, 2018

Paragon CampTune – a handy tool to resize the Boot Camp partition

Recently I ran out of space on a Boot Camp partition with Windows 10 Pro. So I looked around for ways to make more space for Windows by shrinking the macOS partition and enlarging the Windows partition. Apple doesn’t officially support this in Boot Camp without reinstalling Windows, and doing these operations by hand, e.g. with the help of GNU Parted, is time consuming and tedious.

Luckily, I stumbled over Paragon CampTune, a commercial macOS utility (ready for 10.14 Mojave) that automates these tedious tasks and allows to resize the macOS and Boot Camp partitions on the fly, without having to reinstall Windows or macOS.

It finally worked wonderfully, the only irritating thing was that the tool showed a bland error at the first start of the repartitioning process: “Object not found”. After restarting the process with slightly different partition sizes, it could be successfully completed.

I can thus recommend this handy utility as it can save hours of work for a few bucks (ca. 22 USD).

September 19, 2017

macOS: SystemUIServer eating your CPU? Check your Ethernet connection!

Recently, the SystemUIServer process on my MBP running macOS Sierra has started “eating” a lot of CPU, slowing down the whole machine, even making the clock in the top menu bar stop working properly. It usually started using one-digit percentages of the available CPU power, then growing to 10%, 15%, 20%, up to well above 60%, sometimes even 80% and more! It wasn’t a steady growth – it sometimes shrank again, just to grow even further.

The only apparent remedy was to kill the SystemUIServer process (e.g. using the Activity Monitor) from time to time (i.e. every 30 minutes -> there are also scripts to automatically restart SystemUIServer). Its CPU usage then reset to a low one-digit number.

Taking a closer look at the process in the Activity Monitor, I then noticed that the number of (used) ports (so-called “Mach ports“) by the process were steadily growing, once SystemUIServer was started. This was weird, pointing to some kind of leakage. Typically, for a CPU load of around 50%, more than 5000 Mach ports were used.

By coincidence, I then noticed that, unlike expected, my MBP wasn’t actually using Ethernet, but only WiFi. Further investigation then hinted that the according Gigabit Ethernet port on my HP 1810 switch was apparently malfunctioning (or even dead): In the macOS Network Preferences, the Thunderbolt-Ethernet connection was constantly shown as red/disconnected, although the OS was apparently trying to establish a connection again and again (and failed). First, I even suspected a problem with the Thunderbolt-Gigabit-Ethernet adapter itself (it wasn’t the problem here, the adapter seemed to work fine with another Mac and connection).

The solution to this problem thus was:

Connect the Ethernet cable to another, working Ethernet port: Now the SystemUIServer process consumes less than 0.1% CPU again and roughly 400 ports only, both with and without additional WiFi.
Note that both the problem and this solution are reproducible.

Lessons learned:

Sometimes, very unexpected, seemingly unrelated and “small” problems can have big (negative) effects.
Sometimes you need a bit of luck to find the cause of a problem (a web search didn’t bring up the above hint, rather suggested updating or removing faulty apps, buggy extensions and menu widgets. I thus already tried removing or updating some of the suspected apps, extensions and widgets.)
Ports of HP 1810 switches can actually break/fail! Remember the saying: “I got 99 problems, but a switch ain’t one!” – well, in this case, the faulty switch was actually part of the problem and even the initial trigger of the problem! Also remember that HP offers a lifelong warranty on its (good ol’) 1810 switches.
Extra points for you, further research: The fact that the SystemUIServer allocates more and more Mach ports if there’s a malfunctioning Ethernet port (i.e. faulty Ethernet connection or faulty handling of a faulty Ethernet connection by the Thunderbolt-Gigabit-Ethernet adapter) is hinting that this might be an attack vector for a (new?) DoS attack. Perhaps not an easily exploitable one (on the Ethernet or MAC layer, even), but it’s nonetheless something that should actually be handled gracefully by SystemUIServer, not leading to more and more CPU and system resources being consumed.
If you have time to research this further, let me know about your findings!

August 3, 2017September 13, 2017

Using multiple Skype accounts on macOS

With the recent changes in Skype, the “traditional” method of running several Skype instances using different system users doesn’t work anymore (as the the new authentication dialog strangely doesn’t get the focus anymore).

So, in order to use several Skype accounts on macOS (formerly known as Mac OS X), do the following:

Open the Script Editor (in the ‘Utilities’ folder in the ‘Applications’ folder)
Create a new script with the following content:
```
do shell script "open -na /Applications/Skype.app/Contents/MacOS/Skype --args -DataPath '/Users/your_system_user/Library/Application Support/Skype_any_identifier'"
```
Replace your_system_user by your regular macOS user account (see ‘whoami’ in Terminal)
Replace _any_identifier by the according Skype account name, e.g. _myskypename (doesn’t really matter what, just don’t use an empty string)
Please mind the double quotes and single quotes (important!)
Save the script as an application: File.. Save.., choose “Application” as file format, give it a name and store it e.g. in your home directory or in the Applications folder

Repeat these steps for any of your Skype accounts, giving each Skype account a different Skype_any_identifier. You can then start the according Skype instances by double clicking on the according app.

Explanation:

The above script starts a new instance of Skype (which would otherwise be prevented), using the -n argument. Each instance of Skype gets its own directory to store the according account data, using the -DataPath argument.