Hi -
You didn't specify what version of MongoDB you are using, or how you installed it, but I'm going to assume that you built the master branch from source.
I'm not very familiar with the RPi2, but my understanding is that despite using an aarch64 capable core, the user space is still 32-bit.
There are currently no persistent MongoDB storage engines available for 32-bit non-x86 systems, and please note the following caveats:
- 32-bit MongoDB is deprecated as of MongoDB 3.2, and no longer offered on the master branch, which will become MongodB 3.4.
- The only storage engine that works in 32-bit mode is MMAPv1. The WiredTiger storage engine requires 64 bits.
- MMAPv1 is only available on x86 based systems.
On the master branch, you can override this last restriction manually when building MongoDB by passing the --mmapv1=on flag when building from source. However, please note that in 32-bit mode the MMAPv1 storage engine is limited to storing approximately 1GB of data, total. We also do no testing of MMAPv1 on non-x86 platforms.
Thanks,
Andrew