This code is now unmaintained. The replacement code for electrum server is ElectrumX: https://github.com/kyuupichan/electrumx
This document is an easy to follow guide to installing and running your own Electrum server on Linux. It is structured as a series of steps you need to follow, ordered in the most logical way. The next two sections describe some conventions we use in this document and the hardware, software, and expertise requirements.
The most up-to date version of this document is available at:
https://github.com/spesmilo/electrum-server/blob/master/HOWTO.md
In this document, lines starting with a hash sign (#) or a dollar sign ($)
contain commands. Commands starting with a hash should be run as root,
commands starting with a dollar should be run as a normal user (in this
document, we assume that user is called 'bitcoin'). We also assume the
bitcoin user has sudo rights, so we use $ sudo command when we need to.
Strings that are surrounded by "lower than" and "greater than" ( < and > )
should be replaced by the user with something appropriate. For example,
<password> should be replaced by a password. Do not confuse this
notation with shell redirection (command < file or command > file)!
Lines that lack hash or dollar signs are pastes from config files. They should be copied verbatim or adapted without the indentation tab.
apt-get install commands are suggestions for required dependencies.
They conform to an Ubuntu 15.10 system but may well work with Debian
or other versions of Ubuntu.
Expertise. You should be familiar with Linux command line and standard Linux commands. You should have a basic understanding of git and Python packages. You should have knowledge about how to install and configure software on your Linux distribution. You should be able to add commands to your distribution's startup scripts. If one of the commands included in this document is not available or does not perform the operation described here, you are expected to fix the issue so you can continue following this howto.
Software. A recent Linux 64-bit distribution with the following software
installed: python, easy_install, git, standard C/C++
build chain. You will need root access in order to install other software or
Python libraries. Python 2.7 is the minimum supported version.
Hardware. The lightest setup is a pruning server with disk space requirements of about 50 GB for the Electrum database (January 2017). However note that you also need to run bitcoind and keep a copy of the full blockchain, which is roughly 125 GB (January 2017). Ideally you have a machine with 16 GB of RAM and an equal amount of swap. If you have ~2 GB of RAM make sure you limit bitcoind to 8 concurrent connections by disabling incoming connections. electrum-server may bail-out on you from time to time with less than 4 GB of RAM, so you might have to monitor the process and restart it. You can tweak cache sizes in the config to an extend but most RAM will be used to process blocks and catch-up on initial start.
CPU speed is less important than fast I/O speed. electrum-server makes use of one core only leaving spare cycles for bitcoind. Fast single core CPU power helps for the initial block chain import. Any multi-core x86 CPU with CPU Mark / PassMark > 1500 will work (see https://www.cpubenchmark.net/). An ideal setup in February 2016 has 16 GB+ RAM and SSD for good i/o speed.
This step is optional, but for better security and resource separation I
suggest you create a separate user just for running bitcoind and Electrum.
We will also use the ~/bin directory to keep locally installed files
(others might want to use /usr/local/bin instead). We will download source
code files to the ~/src directory.
$ sudo adduser bitcoin --disabled-password
$ sudo apt-get install git
$ sudo su - bitcoin
$ mkdir ~/bin ~/src
$ echo $PATH
If you don't see /home/bitcoin/bin in the output, you should add this line
to your .bashrc, .profile, or .bash_profile, then logout and relogin:
PATH="$HOME/bin:$PATH"
$ exit
We currently recommend bitcoin core 0.15.0 stable. If your package manager does not supply a recent bitcoind or you prefer to compile it yourself, here are some pointers for Ubuntu:
$ sudo apt-get install make bsdmainutils g++ python-leveldb libboost-all-dev libssl-dev libdb++-dev pkg-config libevent-dev
$ sudo su - bitcoin
$ cd ~/src && wget https://bitcoin.org/bin/bitcoin-core-0.15.0/bitcoin-0.15.0.tar.gz
$ sha256sum bitcoin-0.15.0.tar.gz | grep 54b6f54982da97f294d21ad69c6b8624f2cf40d157be0683123b2ba6db2bf2a1
$ tar xfz bitcoin-0.15.0.tar.gz
$ cd bitcoin-0.15.0
$ ./configure --disable-wallet --without-miniupnpc
$ make
$ strip src/bitcoind src/bitcoin-cli src/bitcoin-tx
$ cp -a src/bitcoind src/bitcoin-cli src/bitcoin-tx ~/bin
In order to allow Electrum to "talk" to bitcoind, we need to set up an RPC
username and password for bitcoind. We will then start bitcoind and
wait for it to complete downloading the blockchain.
$ mkdir ~/.bitcoin
$ $EDITOR ~/.bitcoin/bitcoin.conf
Write this in bitcoin.conf:
daemon=1
txindex=1
rpcuser / rpcpassword options are only needed for non-localhost connections. you can consider setting maxconnections if you want to reduce bitcoind bandwidth (as stated above)
If you have an existing installation of bitcoind and have not previously set txindex=1 you need to reindex the blockchain by running
$ bitcoind -reindex
If you already have a freshly indexed copy of the blockchain with txindex start bitcoind:
$ bitcoind
Allow some time to pass for bitcoind to connect to the network and start
downloading blocks. You can check its progress by running:
$ bitcoin-cli getblockchaininfo
Before starting the Electrum server your bitcoind should have processed all blocks and caught up to the current height of the network (not just the headers). You should also set up your system to automatically start bitcoind at boot time, running as the 'bitcoin' user. Check your system documentation to find out the best way to do this.
We will download the latest git snapshot for Electrum to configure and install it:
$ cd ~
$ git clone https://github.com/spesmilo/electrum-server.git
$ cd electrum-server
$ sudo apt-get install python-setuptools
$ sudo ./configure
$ sudo python setup.py install
See the INSTALL file for more information about the configure and install commands.
Electrum server depends on various standard Python libraries and leveldb. These will usually be
installed by calling python setup.py install above. They can be also be installed with your
package manager if you don't want to use the install routine.
$ sudo apt-get install python-setuptools python-openssl python-leveldb libleveldb-dev
$ sudo easy_install jsonrpclib irc plyvel
For the python irc module please note electrum-server currently only supports versions between 11 and 14.0. The setup.py takes care of installing a supported version but be aware of it when installing or upgrading manually.
Regarding leveldb, see the steps in README.leveldb for further details, especially if your system doesn't have the python-leveldb package or if plyvel installation fails.
leveldb should be at least version 1.9.0. Earlier version are believed to be buggy.
Electrum server uses leveldb to store transactions. You can choose how many spent transactions per address you want to store on the server. The default is 100, but there are also servers with 1000 or even 10000. Few addresses have more than 10000 transactions. A limit this high can be considered equivalent to a "full" server. Full servers previously used abe to store the blockchain. The use of abe for electrum servers is now deprecated.
The pruning server uses leveldb and keeps a smaller and faster database by pruning spent transactions. It's a lot quicker to get up and running and requires less maintenance and disk space than abe.
The section in the electrum server configuration file (see step 10) looks like this:
[leveldb]
path = /path/to/your/database
# for each address, history will be pruned if it is longer than this limit
pruning_limit = 100
It's recommended that you fetch a pre-processed leveldb from the net. The "configure" script above will offer you to download a database with pruning limit 100.
You can fetch recent copies of electrum leveldb databases with different pruning limits and further instructions from the Electrum full archival server foundry at: https://foundry.electrum.org/
Alternatively, if you have the time and nerve, you can import the blockchain yourself.
As of April 2014 it takes between two days and over a week to import 300k blocks, depending on CPU speed, I/O speed, and your selected pruning limit.
It's considerably faster and strongly recommended to index in memory. You can use /dev/shm or or create a tmpfs which will also use swap if you run out of memory:
$ sudo mount -t tmpfs -o rw,nodev,nosuid,noatime,size=15000M,mode=0777 none /tmpfs
If you use tmpfs make sure you have enough RAM and swap to cover the size. If you only have 4 GB of RAM but add 15 GB of swap from a file that's fine too; tmpfs is smart enough to swap out the least used parts. It's fine to use a file on an SSD for swap in this case.
It's not recommended to do initial indexing of the database on an SSD because the indexing process does at least 20 TB (!) of disk writes and puts considerable wear-and-tear on an SSD. It's a lot better to use tmpfs and just swap out to disk when necessary.
Databases have grown to roughly 30 GB as of February 2016. Leveldb prunes the database from time to time, so it's not uncommon to see databases ~50% larger at times when it's writing a lot, especially when indexing from the beginning.
[Note: SSL certificates signed by a CA are supported by 2.0 clients.]
To run SSL / HTTPS you need to generate a self-signed certificate using openssl. You could just comment out the SSL / HTTPS ports in the config and run without, but this is not recommended.
Use the sample code below to create a self-signed cert with a recommended validity of 5 years. You may supply any information for your sign request to identify your server. They are not currently checked by the client except for the validity date. When asked for a challenge password just leave it empty and press enter.
$ openssl genrsa -des3 -passout pass:x -out server.pass.key 2048
$ openssl rsa -passin pass:x -in server.pass.key -out server.key
writing RSA key
$ rm server.pass.key
$ openssl req -new -key server.key -out server.csr
...
Country Name (2 letter code) [AU]:US
State or Province Name (full name) [Some-State]:California
Common Name (eg, YOUR name) []: electrum-server.tld
...
A challenge password []:
...
$ openssl x509 -req -days 1825 -in server.csr -signkey server.key -out server.crt
The server.crt file is your certificate suitable for the ssl_certfile= parameter and
server.key corresponds to ssl_keyfile= in your Electrum server config.
Starting with Electrum 1.9, the client will learn and locally cache the SSL certificate for your server upon the first request to prevent man-in-the middle attacks for all further connections.
If your certificate is lost or expires on the server side, you will need to run your server with a different server name and a new certificate. Therefore it's a good idea to make an offline backup copy of your certificate and key in case you need to restore them.
Electrum reads a config file (/etc/electrum.conf) when starting up. This file includes the database setup, bitcoind RPC setup, and a few other options.
The "configure" script listed above will create a config file at /etc/electrum.conf which you can edit to modify the settings.
Go through the config options and set them to your liking. If you intend to run the server publicly have a look at README-IRC.md
Electrum server currently needs quite a few file handles to use leveldb. It also requires file handles for each connection made to the server. It's good practice to increase the open files limit to 128k.
The "configure" script will take care of this and ask you to create a user for running electrum-server.
If you're using the user bitcoin to run electrum and have added it as shown in this document, run
the following code to add the limits to your /etc/security/limits.conf:
echo "bitcoin hard nofile 131072" >> /etc/security/limits.conf
echo "bitcoin soft nofile 131072" >> /etc/security/limits.conf
If you are on Debian > 8.0 Jessie or another distribution based on it, you also need to add these lines in /etc/pam.d/common-session and /etc/pam.d/common-session-noninteractive otherwise the limits in /etc/security/limits.conf will not work:
echo "session required pam_limits.so" >> /etc/pam.d/common-session
echo "session required pam_limits.so" >> /etc/pam.d/common-session-noninteractive
Check if the limits are changed either by logging with the user configured to run Electrum server as. Example:
su - bitcoin
ulimit -n
Or if you use sudo and the user is added to sudoers group:
sudo -u bitcoin -i ulimit -n
Two more things for you to consider:
-
To increase privacy of transactions going through your server you may want to close bitcoind for incoming connections and connect outbound only. Most servers do run full nodes with open incoming connections though.
-
Consider restarting bitcoind (together with electrum-server) on a weekly basis to clear out unconfirmed transactions from the local the memory pool which did not propagate over the network.
The magic moment has come: you can now start your Electrum server as root (it will su to your unprivileged user):
# electrum-server start
Note: If you want to run the server without installing it on your system, just run 'run_electrum_server" as the unprivileged user.
You should see this in the log file:
starting Electrum server
If your blockchain database is out of date Electrum Server will start updating it. You will see something similar to this in the log file:
[09/02/2016-09:58:18] block 397319 (1727 197.37s) 0290aae5dc6395e2c60e8b2c9e48a7ee246cad7d0630d17dd5b54d70a41ffed7 (10.13tx/s, 139.78s/block) (eta 11.5 hours, 240 blocks)
The important pieces to you are at the end. In this example, the server has to calculate 240 more blocks, with an ETA of 11.5 hours. Multiple entries will appear below this one as the server catches back up to the latest block. During this time the server will not accept incoming connections from clients or connect to the IRC channel.
If you want to stop Electrum server, use the 'stop' command:
# electrum-server stop
If your system supports it, you may add electrum-server to the /etc/init.d directory. This will ensure that the server is started and stopped automatically, and that the database is closed safely whenever your machine is rebooted.
# ln -s `which electrum-server` /etc/init.d/electrum-server
# update-rc.d electrum-server defaults
We will assume you have a working Electrum client, a wallet, and some transaction history. You should start the client and click on the green checkmark (last button on the right of the status bar) to open the Server selection window. If your server is public, you should see it in the list and you can select it. If you server is private, you need to enter its IP or hostname and the port. Press 'Ok' and the client will disconnect from the current server and connect to your new Electrum server. You should see your addresses and transactions history. You can see the number of blocks and response time in the server selection window. You should send/receive some bitcoins to confirm that everything is working properly.
Say hi to the dev crew, other server operators, and fans on irc.freenode.net #electrum and we'll try to congratulate you on supporting the community by running an Electrum node.
If you're operating a public Electrum server please subscribe to or regularly check the following thread: https://bitcointalk.org/index.php?topic=85475.0 It'll contain announcements about important updates to Electrum server required for a smooth user experience.