The script [log2ram](https://github.com/azlux/log2ram) can work on every linux system. So you can use it with your own daemon manager if you don't have systemd.
-`SIZE`: defines the size the log folder will reserve into the RAM (default is 40M).
-`USE_RSYNC`: Can be set to `true` if you prefer ´rsync´ rather than ´cp´. I use the command `cp -u` and `rsync -X`, I don't copy the all folder every time for optimization.
By default Log2Ram writes to the HardDisk every hour. If you think this is too much, you can make the write every day by moving the cron file to daily: `sudo mv /etc/cron.hourly/log2ram /etc/cron.daily/log2ram`.
If you have issue with apache2, you can try to add `apache2.service` next to other services on the `Before` parameter in `/etc/systemd/system/log2ram.service` it will solve the pb