This tip worked just fine for me:
germaniac(reporter)
2015-02-27 01:11
"My system has 8 GB of RAM and I had a swapfile of 1.0 GB in total. After increasing it to a - non-reasonable value - of 8 GB, DayZ does not crash anymore.
I believe it's a bug that DayZ, which is still a 32 Bit application, can somehow gather more than 4 GB of Ram from the system.
To circumvent, just temporarily increase your systems swap file so that you have at least 9 or 10 GB of (virtual) RAM."