I'm trying to set up Armory but it wants to download the whole blockchain. The thing is I already have the blockchain downloaded on the same machine for bitcoin-qt. Is there any way to get Armory to use the blockchain I already have, both to save space and avoid waiting for hours?
If your settings are correct, try restarting Armory, and let it run for a few minutes. I had the same concern thinking that Armory was redownloading the blockchain, but it was actually reading from the harddrive (Listen to the harddrive).
After roughly 10 minutes, the block synchronisation went from 0% very quickly to 100%, then the status changed to "Connected". Next Armory synced the transaction history for another 10 to 15 mins.
I guess there is a user experience bug here. Armory should have had a user friendly message somewhere saying something like: "Verifying local blockchain".
In the Armory settings, you can specify the location of bitcoin-qt installdir, and the home directory of bitcoin (where the blockchain is stored).
Then it uses the already downloaded chain.
With respect to user7220, I think that answer is wrong. I moved Armory and my QT native blockchain to my E: drive, and Armory started rebuilding the QT chain on C: drive. After some checking, I found that you can add the path on the command line, using " --satoshi-datadir=[bitcoindatapath]" as a switch. My Armory shortcut is now
"C:\Program Files (x86)\Armory\ArmoryQt.exe" --datadir="e:/armory" --satoshi-datadir="e:\bitcoin"
The armory executables are on C: but the freaking huge blockchains are on my outboard E: drive for both Armory and BitcoinQT. Now my C: drive has space and I can install a wallet that does not require the blockchain, and a copy of the blockchain (bravo, Devs).