Deleting Apple System Logs to Speed Up Zsh

August 17, 2012

For the past year I have been using the oh-my-zsh framework to configure my zsh prompt and environment. My one complaint about oh-my-zsh is its slowness spawning a new shell. When I use Cmd-T in iTerm to create a new tab I often have to wait 3 or 4 or even 5 seconds for that new shell to become active. This is unacceptable.

Searching for "speed up oh-my-zsh" lead me to the zsh stars incredibly slowly discussion. From there I went to speed up a slow terminal by clearing log files. My /private/var/logs/asl directory did have some *.asl or Apple System Log Files. Using the suggested rm command I deleted all *.asl files in my /private/var/logs/asl directory.

$ sudo rm /private/var/logs/asl/*.asl

Prior to deleting the *.asl files I tested the start time of my shell like this:

$ time zsh -i -c exit
zsh -i -c exit 0.35s user 0.40s system 12% cpu 5.953 total

After deleting the *.asl files the time dropped considerably:

$ time zsh -i -c exit
zsh -i -c exit 0.27s user 0.21s system 96% cpu 0.496 total

NB: As with any low-level mucking about on your computer, proceed at your own risk. I don't fully understand everything that ASL files are used for. Deleting the set my computer has accumulated seems to have considerably speed ip spawning new shells without any detrimental side effects. Your experience may vary.

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Mark H. Nichols

I am a husband, cellist, code prole, nerd, technologist, and all around good guy living and working in fly-over country. You should follow me on Twitter.