Before you can use MongoDB, you need to create a /data/db folder because MongoDB expects this directory (/data/db) on your machine to save the data. But Apple has already depreciated this directory on Catalina/BigSur machines and created a new volume on macOS Catalina for security purposes. I upgraded my computer to macOS Catalina and I am facing problems running MongoDB. As you all know Mongo puts its databases in /data/db. In the latest macOS Catalina, they have removed all access. Uh, oh, what’s happening. This problem happens for Mac OS X version Catalina or after as a new update makes the root folder no longer writable. “With macOS Catalina, you can no longer store files or data in the read-only system volume, nor can you write to the “root” directory ( / ) from the command line, such as with Terminal.” See. A guide to show you how to install MongoDB on Mac OS X. 问题I have installed mongodb on my mac Catalina 10.15. I have php7.3 version installed as well. The instructions we give on installing MongoDB here and other places. But with Catalina there are issues with anyone creating a directory in this path.
I recently bought a new iMac and moved all of my files over using Time Machine. The migration went really well overall and within a few hours I had my development machine up and running. After starting an application I’m building I quickly realized that I couldn’t get MongoDB to start. Running the following command resulted in an error about the data/db directory being read-only:
I tried every chmod and chown command known to man and woman kind, tried manually changing security in Finder, compared security to my other iMac (they were the same), and tried a bunch of other things as well. But, try as I might I still saw the read-only folder error when trying to start the server….very frustrating. I found a lot of posts with the same issue but they all solved it by changing security on the folder. That wasn’t the problem on my machine.
After doing more research I found out that Catalina added a new volume to the hard drive and creates a special folder where the MongoDB files need to go. The new folder is:
The MongoDB files can then go at:
I ran the following commands to install the latest version of MongoDB using Homebrew (see https://github.com/mongodb/homebrew-brew for more details):
I then went into the MongoDB config file at /usr/local/etc/mongod.conf. Note that it’s possible yours may be located in a different location based on how you installed MongoDB. I changed the dbPath value to the following and copied my existing DB files into the folder:
Finally, I made sure my account had the proper access to the folder by running chown (something I had tried many times earlier but on a folder outside of /System/Volumes/Data): Download catman sub indo.
How To Install Mongodb On Macos Catalina
After that I was able to start MongoDB and everything was back to normal. Hopefully this saves someone a few hours – I wasted way too much time on the issue. 🙂