When a lot of things are running at once, hitting the open files limit on MacOS makes things start crashing. Running MacOS Server is supposed to help, but its configuration changes are inadequate if a lot of non-server activity is also going on. Every version of MacOS seems to have a different way of changing the open files limit. Here are some pages that try to follow the changes between versions.
Yesterday, a friend brought me a second-hand iMac G5 that he could not get the password for. He wanted to erase and reinstall the operating system. We had ordered a Leopard install disk, but the iMac kept ejecting it. I copied the install disk to a USB flash drive, but it did not appear in the list of startup disks. The instructions on the page Boot a PowerPC Apple from USB provided a workaround:
PATH is a variable that determines where the system looks for commands. Most guides I found suggest setting this in a Bash configuration file. But this only affects commands run in a Bash terminal. Global paths on macOS High Sierra are set in /etc/paths. You can also add a file to /etc/paths.d. Files in that directory have their paths included automatically.
I was used to flushing memcached by connecting with telnet and issuing the flush_all command. Today I found that the telnet command has been removed from macOS High Sierra. Netcat works just as well for sending text over a TCP connection and is available on High Sierra.
The Bitcoin block chain had reached 85 gigabytes last week, so it was no longer practical to run a full node client on my laptop. A full node client verifies a transaction by checking earlier transactions all the way back to when the network first issued the funds used in the current transaction. To do this, it first has to download every block of transactions in the chain. The alternative is a client that uses simplified payment verification (SPV).
When I tried to use Airplay to make my TV a second display, the TV went blank. None of the mirroring options were shown in the Airplay menu. I called Apple support, but Airplay mysteriously started working during the call. Yesterday, the problem was back. I found the solution in an Apple support community post. There seems to be a bug in El Capitan that prevents Airplay from being used as a second display if there is an invalid login item.
I’m working with a MEAN app on Mac OS X El Capitan Version 10.11.3. Every time I restart the computer, the app crashes, saying, “Too many open files.” I have to run this command in the terminal to get the app to start:
ulimit -n 1024
Server 5.0.15 gets stuck configuring Xcode 7.2.1 unless Xcode is run at least once as root: https://forums.developer.apple.com/thread/34683.
Don’t use Audiobook Builder 1.5.4 to create audiobooks on a Mac. It always adds a blank JPEG track to the audio file. Audiobook Binder 2.1 works properly and is free. No idea why LibriVox recommends Audiobook Builder. Here are instructions for getting a refund: http://www.imore.com/how-to-get-refund-itunes-app-store.