Constantly updating and scanning the blockchain for newly discovered blocks is eating up a lot of memory on my Mac. Can I run simplewallet and bitmonerod from my 1 TB external HDD and only when its plugged in?
I cannot afford to have the full node eating away at my memory anymore.
If this is doable, how do I transfer the data from my internal hard drive to my external HDD?
Couple things... is it eating away at your memory (RAM) or storage (disk space)?
If you mean RAM, the answer is no. The computer memory used to run simplewallet and the daemon are not dependent on where things are being stored, at least in any measurable sense.
If you mean disk space, yes, kind of. What I mean by this is that you should still "run" bitmonerod and simplewallet from your primary disk, but specify a data directory on your external hard drive for bitmonerod. On macOS, this involves running the daemon like dEBRUYNE said, as such:
./bitmonerod --data-dir /Volumes/<my external HDD>
Note that you should run this command in the Terminal from the directory where you've save the bitmonerod executable.
To figure out what goes in <my external HDD>, open a Terminal and type
ls /Volumes
This should display a list of all connected volumes. Find your HDD (say, MyHDD), then do
./bitmonerod --data-dir /Volumes/MyHDD
Note that if you have already synced a blockchain in a previous location, you may need to move it or resync.
This is certainly possible. Simply launch bitmonerod with the --data-dir path/to/new/blockchain/folder argument. Thus, the full command is as follows:
./bitmonerod --data-dir path/to/new/blockchain/folder
Simplewallet will simply connect to the daemon that is running on your system, regardless of where the blockchain is stored.
For what it's worth, bitmonerod uses <100 MB of RAM when fully synced. However, given that you have a HDD, it might be resource intensive for your CPU.
