Documentation: erigon.gitbook.io

Erigon is an implementation of Ethereum (execution layer with embeddable consensus layer), on the efficiency frontier. Archive Node by default.

• System Requirements

• Usage

  • Getting Started
  • Logging
  • Testnets
  • Block Production
  • Windows
  • GoDoc
  • Beacon Chain
  • Dev Chain
  • Caplin (Internal Consensus Layer)

• Key features

  • More Efficient State Storage
  • Faster Initial Sync
  • JSON-RPC daemon
  • Run all components by docker-compose
  • Grafana dashboard
  • Internal Consensus Layer

• Documentation

• FAQ

• Getting in touch

  • Erigon Discord Server
  • Reporting security issues/concerns
  • Team

• Known issues

  • htop shows incorrect memory usage

Disclaimer: this software is currently a tech preview. We will do our best to keep it stable and make no breaking changes but we don't guarantee anything. Things can and will break.

Important defaults: Erigon is an Archive Node by default (to remove history see: --prune flags in erigon --help). We don't allow change this flag after first start.

In-depth links are marked by the microscope sign (🔬)

• For an Archive node of Ethereum Mainnet we recommend >=3.5TB storage space: 2.3TiB state (as of March 2024), 643GiB snapshots (can symlink or mount folder <datadir>/snapshots to another disk), 200GB temp files (can symlink or mount folder <datadir>/temp to another disk). Ethereum Mainnet Full node (see Pruned Node): 1.1TiB not including temp files (June 2024).

• Gnosis Chain Archive: 1.7TiB (March 2024). Gnosis Chain Full node (see Pruned Node): 300GiB (June 2024).

• Polygon Mainnet Archive: 8.5TiB (December 2023). Polygon Mainnet Full node (see Pruned Node) with --prune.*.older 15768000: 5.1Tb (September 2023).

SSD or NVMe. Do not recommend HDD - on HDD Erigon will always stay N blocks behind chain tip, but not fall behind. Bear in mind that SSD performance deteriorates when close to capacity.

RAM: >=16GB, 64-bit architecture.

Golang version >= 1.21; GCC 10+ or Clang; On Linux: kernel > v4

🔬 more details on disk storage here and here.

For building the latest release (this will be suitable for most users just wanting to run a node):

git clone --branch release/<x.xx> --single-branch https://github.com/erigontech/erigon.git
cd erigon
make erigon
./build/bin/erigon

You can check the list of releases for release notes.

For building the bleeding edge development branch:

git clone --recurse-submodules https://github.com/erigontech/erigon.git
cd erigon
git checkout main
make erigon
./build/bin/erigon

Default --snapshots for mainnet, gnosis, chiado. Other networks now have default --snapshots=false. Increase download speed by flag --torrent.download.rate=20mb. 🔬 See Downloader docs

Use --datadir to choose where to store data.

Use --chain=gnosis for Gnosis Chain, --chain=bor-mainnet for Polygon Mainnet, and --chain=amoy for Polygon Amoy. For Gnosis Chain you need a Consensus Layer client alongside Erigon (https://docs.gnosischain.com/node/manual/beacon).

Running make help will list and describe the convenience commands available in the Makefile.

• chaindata: recent blocks, state, recent state history. low-latency disk recommended.
• snapshots: old blocks, old state history. can symlink/mount it to cheaper disk. mostly immutable. must have ~100gb free space (for merge recent files to bigger one).
• temp: can grow to ~100gb, but usually empty. can symlink/mount it to cheaper disk.
• txpool: pending transactions. safe to remove.
• nodes: p2p peers. safe to remove.

Flags:

• verbosity
• log.console.verbosity (overriding alias for verbosity)
• log.json
• log.console.json (alias for log.json)
• log.dir.path
• log.dir.prefix
• log.dir.verbosity
• log.dir.json

In order to log only to the stdout/stderr the --verbosity (or log.console.verbosity) flag can be used to supply an int value specifying the highest output log level:

  LvlCrit = 0
  LvlError = 1
  LvlWarn = 2
  LvlInfo = 3
  LvlDebug = 4
  LvlTrace = 5

To set an output dir for logs to be collected on disk, please set --log.dir.path If you want to change the filename produced from erigon you should also set the --log.dir.prefix flag to an alternate name. The flag --log.dir.verbosity is also available to control the verbosity of this logging, with the same int value as above, or the string value e.g. ' debug' or 'info'. Default verbosity is 'debug' (4), for disk logging.

Log format can be set to json by the use of the boolean flags log.json or log.console.json, or for the disk output --log.dir.json.

Erigon by default is "all in one binary" solution, but it's possible start TxPool as separated processes. Same true about: JSON RPC layer (RPCDaemon), p2p layer (Sentry), history download layer (Downloader), consensus. Don't start services as separated processes unless you have clear reason for it: resource limiting, scale, replace by your own implementation, security. How to start Erigon's services as separated processes, see in docker-compose.yml.

On Ethereum Mainnet and Sepolia, the Engine API can be disabled in favour of the Erigon native Embedded Consensus Layer. If you want to use the internal Consensus Layer, run Erigon with flag --internalcl. Warning: Staking (block production) is not possible with the embedded CL.

If you would like to give Erigon a try, but do not have spare 2TB on your drive, a good option is to start syncing one of the public testnets, Sepolia. It syncs much quicker, and does not take so much disk space:

git clone --recurse-submodules -j8 https://github.com/erigontech/erigon.git
cd erigon
make erigon
./build/bin/erigon --datadir=<your_datadir> --chain=sepolia

Please note the --datadir option that allows you to store Erigon files in a non-default location, in this example, in sepolia subdirectory of the current directory. Name of the directory --datadir does not have to match the name of the chain in --chain.

Disclaimer: Not supported/tested for Gnosis Chain and Polygon Network (In Progress)

Support only remote-miners.

• To enable, add --mine --miner.etherbase=... or --mine --miner.miner.sigkey=... flags.
• Other supported options: --miner.extradata, --miner.notify, --miner.gaslimit, --miner.gasprice , --miner.gastarget
• JSON-RPC supports methods: eth_coinbase , eth_hashrate, eth_mining, eth_getWork, eth_submitWork, eth_submitHashrate
• JSON-RPC supports websocket methods: newPendingTransaction

🔬 Detailed explanation is here.

Windows users may run erigon in 3 possible ways:

• Build executable binaries natively for Windows using provided wmake.ps1 PowerShell script. Usage syntax is the same as make command so you have to run .\wmake.ps1 [-target] <targetname>. Example: .\wmake.ps1 erigon builds erigon executable. All binaries are placed in .\build\bin\ subfolder. There are some requirements for a successful native build on windows :

  • Git for Windows must be installed. If you're cloning this repository is very likely you already have it
  • GO Programming Language must be installed. Minimum required version is 1.21
  • GNU CC Compiler at least version 13 (is highly suggested that you install chocolatey package manager - see following point)
  • If you need to build MDBX tools (i.e. .\wmake.ps1 db-tools) then Chocolatey package manager for Windows must be installed. By Chocolatey you need to install the following components : cmake, make, mingw by choco install cmake make mingw. Make sure Windows System "Path" variable has: C:\ProgramData\chocolatey\lib\mingw\tools\install\mingw64\bin

  Important note about Anti-Viruses During MinGW's compiler detection phase some temporary executables are generated to test compiler capabilities. It's been reported some anti-virus programs detect those files as possibly infected by Win64/Kryptic.CIS trojan horse (or a variant of it). Although those are false positives we have no control over 100+ vendors of security products for Windows and their respective detection algorithms and we understand this might make your experience with Windows builds uncomfortable. To workaround the issue you might either set exclusions for your antivirus specifically for build\bin\mdbx\CMakeFiles sub-folder of the cloned repo or you can run erigon using the following other two options

• Use Docker : see docker-compose.yml

• Use WSL (Windows Subsystem for Linux) strictly on version 2. Under this option you can build Erigon just as you would on a regular Linux distribution. You can point your data also to any of the mounted Windows partitions ( eg. /mnt/c/[...], /mnt/d/[...] etc) but in such case be advised performance is impacted: this is due to the fact those mount points use DrvFS which is a network file system and, additionally, MDBX locks the db for exclusive access which implies only one process at a time can access data. This has consequences on the running of rpcdaemon which has to be configured as Remote DB even if it is executed on the very same computer. If instead your data is hosted on the native Linux filesystem non limitations apply. Please also note the default WSL2 environment has its own IP address which does not match the one of the network interface of Windows host: take this into account when configuring NAT for port 30303 on your router.

You can set Erigon flags through a YAML or TOML configuration file with the flag --config. The flags set in the configuration file can be overwritten by writing the flags directly on Erigon command line

./build/bin/erigon --config ./config.yaml --chain=sepolia

Assuming we have chain : "mainnet" in our configuration file, by adding --chain=sepolia allows the overwrite of the flag inside of the yaml configuration file and sets the chain to sepolia

Example of setting up TOML config file

datadir = 'your datadir'
port = 1111
chain = "mainnet"
http = true
"private.api.addr"="localhost:9090"

"http.api" = ["eth","debug","net"]

Example of setting up a YAML config file

datadir : 'your datadir'
port : 1111
chain : "mainnet"
http : true
private.api.addr : "localhost:9090"

http.api : ["eth","debug","net"]

Erigon can be used as an Execution Layer (EL) for Consensus Layer clients (CL). Default configuration is OK.

If your CL client is on a different device, add --authrpc.addr 0.0.0.0 (Engine API listens on localhost by default) as well as --authrpc.vhosts <CL host> where <CL host> is your source host or any.

In order to establish a secure connection between the Consensus Layer and the Execution Layer, a JWT secret key is automatically generated.

The JWT secret key will be present in the datadir by default under the name of jwt.hex and its path can be specified with the flag --authrpc.jwtsecret.

This piece of info needs to be specified in the Consensus Layer as well in order to establish connection successfully. More information can be found here.

Once Erigon is running, you need to point your CL client to <erigon address>:8551, where <erigon address> is either localhost or the IP address of the device running Erigon, and also point to the JWT secret path created by Erigon.

Caplin is a full-fledged validating Consensus Client like Prysm, Lighthouse, Teku, Nimbus and Lodestar. Its goal is:

• provide better stability
• Validation of the chain
• Stay in sync
• keep the execution of blocks on chain tip
• serve the Beacon API using a fast and compact data model alongside low CPU and memory usage.

The main reason why developed a new Consensus Layer is to experiment with the possible benefits that could come with it. For example, The Engine API does not work well with Erigon. The Engine API sends data one block at a time, which does not suit how Erigon works. Erigon is designed to handle many blocks simultaneously and needs to sort and process data efficiently. Therefore, it would be better for Erigon to handle the blocks independently instead of relying on the Engine API.

Caplin is be enabled by default. to disable it and enable the Engine API, use the --externalcl flag. from that point on, an external Consensus Layer will not be need anymore.

Caplin also has an archivial mode for historical states and blocks. it can be enabled through the --caplin.archive flag. In order to enable the caplin's Beacon API, the flag --beacon.api=<namespaces> must be added. e.g: --beacon.api=beacon,builder,config,debug,node,validator,lighthouse will enable all endpoints. **NOTE: Caplin is not staking-ready so aggregation endpoints are still to be implemented. Additionally enabling the Beacon API will lead to a 6 GB higher RAM usage.

Define 6 flags to avoid conflicts: --datadir --port --http.port --authrpc.port --torrent.port --private.api.addr. Example of multiple chains on the same machine:

# mainnet
./build/bin/erigon --datadir="<your_mainnet_data_path>" --chain=mainnet --port=30303 --http.port=8545 --authrpc.port=8551 --torrent.port=42069 --private.api.addr=127.0.0.1:9090 --http --ws --http.api=eth,debug,net,trace,web3,erigon


# sepolia
./build/bin/erigon --datadir="<your_sepolia_data_path>" --chain=sepolia --port=30304 --http.port=8546 --authrpc.port=8552 --torrent.port=42068 --private.api.addr=127.0.0.1:9091 --http --ws --http.api=eth,debug,net,trace,web3,erigon

Quote your path if it has spaces.

🔬 Detailed explanation is DEV_CHAIN.

🔬 See more detailed overview of functionality and current limitations. It is being updated on recurring basis.

Flat KV storage. Erigon uses a key-value database and storing accounts and storage in a simple way.

🔬 See our detailed DB walkthrough here.

Preprocessing. For some operations, Erigon uses temporary files to preprocess data before inserting it into the main DB. That reduces write amplification and DB inserts are orders of magnitude quicker.

🔬 See our detailed ETL explanation here.

Plain state.

Single accounts/state trie. Erigon uses a single Merkle trie for both accounts and the storage.

Erigon uses a rearchitected full sync algorithm from Go-Ethereum that is split into "stages".

🔬 See more detailed explanation in the Staged Sync Readme

It uses the same network primitives and is compatible with regular go-ethereum nodes that are using full sync, you do not need any special sync capabilities for Erigon to sync.

When reimagining the full sync, with focus on batching data together and minimize DB overwrites. That makes it possible to sync Ethereum mainnet in under 2 days if you have a fast enough network connection and an SSD drive.

Examples of stages are:

• Downloading headers;

• Downloading block bodies;

• Recovering senders' addresses;

• Executing blocks;

• Validating root hashes and building intermediate hashes for the state Merkle trie;

• [...]

Most of Erigon's components (txpool, rpcdaemon, snapshots downloader, sentry, ...) can work inside Erigon and as independent process.

To enable built-in RPC server: --http and --ws (sharing same port with http)

Run RPCDaemon as separated process: this daemon can use local DB (with running Erigon or on snapshot of a database) or remote DB (run on another server). 🔬 See RPC-Daemon docs

This works regardless of whether RPC daemon is on the same computer with Erigon, or on a different one. They use TPC socket connection to pass data between them. To use this mode, run Erigon in one terminal window

make erigon
./build/bin/erigon --private.api.addr=localhost:9090 --http=false
make rpcdaemon
./build/bin/rpcdaemon --private.api.addr=localhost:9090 --http.api=eth,erigon,web3,net,debug,trace,txpool

9090 erigon, 9091 sentry, 9092 consensus engine, 9093 torrent downloader, 9094 transactions pool

Supported JSON-RPC calls (eth, debug , net, web3):

For a details on the implementation status of each command, see this table.

Docker allows for building and running Erigon via containers. This alleviates the need for installing build dependencies onto the host OS.

User UID/GID need to be synchronized between the host OS and container so files are written with correct permission.

You may wish to setup a dedicated user/group on the host OS, in which case the following make targets are available.

# create "erigon" user
make user_linux
# or
make user_macos

There is a .env.example file in the root of the repo.

• DOCKER_UID - The UID of the docker user
• DOCKER_GID - The GID of the docker user
• XDG_DATA_HOME - The data directory which will be mounted to the docker containers

If not specified, the UID/GID will use the current user.

A good choice for XDG_DATA_HOME is to use the ~erigon/.ethereum directory created by helper targets make user_linux or make user_macos.

In all cases, XDG_DATA_HOME (specified or default) must be writeable by the user UID/GID in docker, which will be determined by the DOCKER_UID and DOCKER_GID at build time.

If a build or service startup is failing due to permissions, check that all the directories, UID, and GID controlled by these environment variables are correct.

Next command starts: Erigon on port 30303, rpcdaemon on port 8545, prometheus on port 9090, and grafana on port 3000.

#
# Will mount ~/.local/share/erigon to /home/erigon/.local/share/erigon inside container
#
make docker-compose

#
# or
#
# if you want to use a custom data directory
# or, if you want to use different uid/gid for a dedicated user
#
# To solve this, pass in the uid/gid parameters into the container.
#
# DOCKER_UID: the user id
# DOCKER_GID: the group id
# XDG_DATA_HOME: the data directory (default: ~/.local/share)
#
# Note: /preferred/data/folder must be read/writeable on host OS by user with UID/GID given
#       if you followed above instructions
#
# Note: uid/gid syntax below will automatically use uid/gid of running user so this syntax
#       is intended to be run via the dedicated user setup earlier
#
DOCKER_UID=$(id -u) DOCKER_GID=$(id -g) XDG_DATA_HOME=/preferred/data/folder DOCKER_BUILDKIT=1 COMPOSE_DOCKER_CLI_BUILD=1 make docker-compose

#
# if you want to run the docker, but you are not logged in as the $ERIGON_USER
# then you'll need to adjust the syntax above to grab the correct uid/gid
#
# To run the command via another user, use
#
ERIGON_USER=erigon
sudo -u ${ERIGON_USER} DOCKER_UID=$(id -u ${ERIGON_USER}) DOCKER_GID=$(id -g ${ERIGON_USER}) XDG_DATA_HOME=~${ERIGON_USER}/.ethereum DOCKER_BUILDKIT=1 COMPOSE_DOCKER_CLI_BUILD=1 make docker-compose

Makefile creates the initial directories for erigon, prometheus and grafana. The PID namespace is shared between erigon and rpcdaemon which is required to open Erigon's DB from another process (RPCDaemon local-mode). See: https://github.com/erigontech/erigon/pull/2392/files

If your docker installation requires the docker daemon to run as root (which is by default), you will need to prefix the command above with sudo. However, it is sometimes recommended running docker (and therefore its containers) as a non-root user for security reasons. For more information about how to do this, refer to this article.

Windows support for docker-compose is not ready yet. Please help us with .ps1 port.

docker compose up prometheus grafana, detailed docs.

old data

Disabled by default. To enable see ./build/bin/erigon --help for flags --prune

The ./docs directory includes a lot of useful but outdated documentation. For code located in the ./cmd directory, their respective documentation can be found in ./cmd/*/README.md. A more recent collation of developments and happenings in Erigon can be found in the Erigon Blog.

• Baseline (ext4 SSD): 16Gb RAM sync takes 6 days, 32Gb - 5 days, 64Gb - 4 days
• +1 day on "zfs compression=off". +2 days on "zfs compression=on" (2x compression ratio). +3 days on btrfs.
• -1 day on NVMe

Detailed explanation: ./docs/programmers_guide/db_faq.md

Typically, 30303 and 30304 are exposed to the internet to allow incoming peering connections. 9090 is exposed only internally for rpcdaemon or other connections, (e.g. rpcdaemon -> erigon). Port 8551 (JWT authenticated) is exposed only internally for Engine API JSON-RPC queries from the Consensus Layer node.

In order to configure the ports, use:

   --caplin.discovery.addr value                                                    Address for Caplin DISCV5 protocol (default: "127.0.0.1")
   --caplin.discovery.port value                                                    Port for Caplin DISCV5 protocol (default: 4000)
   --caplin.discovery.tcpport value                                                 TCP Port for Caplin DISCV5 protocol (default: 4001)

Optional flags can be enabled that enable pprof or metrics (or both) - however, they both run on 6060 by default, so

you'll have to change one if you want to run both at the same time. use --help with the binary for more info.

Reserved for future use: gRPC ports: 9092 consensus engine, 9093 snapshot downloader, 9094 TxPool

0.0.0.0/8             "This" Network             RFC 1122, Section 3.2.1.3
10.0.0.0/8            Private-Use Networks       RFC 1918
100.64.0.0/10         Carrier-Grade NAT (CGN)    RFC 6598, Section 7
127.16.0.0/12         Private-Use Networks       RFC 1918
169.254.0.0/16        Link Local                 RFC 3927
172.16.0.0/12         Private-Use Networks       RFC 1918
192.0.0.0/24          IETF Protocol Assignments  RFC 5736
192.0.2.0/24          TEST-NET-1                 RFC 5737
192.88.99.0/24        6to4 Relay Anycast         RFC 3068
192.168.0.0/16        Private-Use Networks       RFC 1918
198.18.0.0/15         Network Interconnect
Device Benchmark Testing   RFC 2544
198.51.100.0/24       TEST-NET-2                 RFC 5737
203.0.113.0/24        TEST-NET-3                 RFC 5737
224.0.0.0/4           Multicast                  RFC 3171
240.0.0.0/4           Reserved for Future Use    RFC 1112, Section 4
255.255.255.255/32    Limited Broadcast          RFC 919, Section 7
RFC 922, Section 7

Same in IpTables syntax

Running erigon from build/bin as a separate user might produce an error:

error while loading shared libraries: libsilkworm_capi.so: cannot open shared object file: No such file or directory

The library needs to be installed for another user using make DIST=<path> install. You could use $HOME/erigon or /opt/erigon as the installation path, for example:

make DIST=/opt/erigon install

and then run /opt/erigon/erigon.

• Get stack trace: kill -SIGUSR1 <pid>, get trace and stop: kill -6 <pid>
• Get CPU profiling: add --pprof flag run go tool pprof -png http://127.0.0.1:6060/debug/pprof/profile\?seconds\=20 > cpu.png
• Get RAM profiling: add --pprof flag run go tool pprof -inuse_space -png http://127.0.0.1:6060/debug/pprof/heap > mem.png

🔬 Detailed explanation is here.

Docker uses user erigon with UID/GID 1000 (for security reasons). You can see this user being created in the Dockerfile. Can fix by giving a host's user ownership of the folder, where the host's user UID/GID is the same as the docker's user UID/GID (1000). More details in post

• --txpool.nolocals=true
• don't add admin in --http.api list
• to increase throughput may need increase/decrease: --db.read.concurrency, --rpc.batch.concurrency, --rpc.batch.limit

https://github.com/mathMakesArt/Erigon-on-RPi-4

post

The main discussions are happening on our Discord server. To get an invite, send an email to bloxster [at] proton.me with your name, occupation, a brief explanation of why you want to join the Discord, and how you heard about Erigon.

Send an email to security [at] torquem.ch.

Erigon's internal DB (MDBX) using MemoryMap - when OS does manage all read, write, cache operations instead of Application (linux , windows)

htop on column res shows memory of "App + OS used to hold page cache for given App", but it's not informative, because if htop says that app using 90% of memory you still can run 3 more instances of app on the same machine - because most of that 90% is "OS pages cache". OS automatically frees this cache any time it needs memory. Smaller "page cache size" may not impact performance of Erigon at all.

Next tools show correct memory usage of Erigon:

• vmmap -summary PID | grep -i "Physical footprint". Without grep you can see details

  • section MALLOC ZONE column Resident Size shows App memory usage, section REGION TYPE column Resident Size shows OS pages cache size.

• Prometheus dashboard shows memory of Go app without OS pages cache (make prometheus, open in browser localhost:3000, credentials admin/admin)

• cat /proc/<PID>/smaps

  Erigon uses ~4Gb of RAM during genesis sync and ~1Gb during normal work. OS pages cache can utilize unlimited amount of memory.

  Warning: Multiple instances of Erigon on same machine will touch Disk concurrently, it impacts performance - one of main Erigon optimisations: "reduce Disk random access". "Blocks Execution stage" still does many random reads - this is reason why it's slowest stage. We do not recommend running multiple genesis syncs on same Disk. If genesis sync passed, then it's fine to run multiple Erigon instances on same Disk.

Please read #1516 (comment) In short: network-disks are bad for blocks execution - because blocks execution reading data from db non-parallel non-batched way.

For example: btrfs's autodefrag option - may increase write IO 100x times

Gnome Tracker - detecting miners and kill them.

For anyone else that was getting the BuildKit error when trying to start Erigon the old way you can use the below...

XDG_DATA_HOME=/preferred/data/folder DOCKER_BUILDKIT=1 COMPOSE_DOCKER_CLI_BUILD=1 make docker-compose

Git branch main. Just start erigon as you usually do.

RAM requirement is higher: 32gb and better 64gb. We will work on this topic a bit later.

Golang 1.21

Almost all RPC methods are implemented - if something doesn't work - just drop it on our head.

Supported networks: all.

• Sync from scratch doesn't require re-exec all history. Latest state and it's history are in snapshots - can download.
• ExecutionStage - now including many E2 stages: stage_hash_state, stage_trie, stage_log_index, stage_history_index, stage_trace_index
• E3 can execute 1 historical transaction - without executing it's block - because history/indices have transaction-granularity, instead of block-granularity.
• E3 doesn't store Logs (aka Receipts) - it always re-executing historical txn (but it's cheaper then in E2 - see point above). Known perf issues: #10747
• --sync.loop.block.limit is enabled by default. (Default: 5_000. Set --sync.loop.block.limit=10_000 --batchSize=2g to increase sync speed on good hardware).
• datadir/chaindata is small now - to prevent it's grow: we recommend set --batchSize <= 2G. And it's fine to rm -rf chaindata
• can symlink/mount latest state to fast drive and history to cheap drive
• Archive Node is default. Full Node: --prune.mode=full, Minimal Node (EIP-4444): --prune.mode=minimal

• don't rm -rf downloader - it will cause re-downloading of files: #10976

datadir        
    chaindata   # "Recently-updated Latest State" and "Recent History"
    snapshots   
        domain    # Latest State: link to fast disk
        history   # Historical values 
        idx       # InvertedIndices: can search/filtering/union/intersect them - to find historical data. like eth_getLogs or trace_transaction
        accessors # Additional (generated) indices of history - have "random-touch" read-pattern. They can serve only `Get` requests (no search/filters).
    temp # buffers to sort data >> RAM. sequential-buffered IO - is slow-disk-friendly
   
# There is 4 domains: account, storage, code, commitment 

If you can afford store datadir on 1 nvme-raid - great. If can't - it's possible to store history on cheap drive.

# place (or ln -s) `datadir` on slow disk. link some sub-folders to fast disk.
# Example: what need link to fast disk to speedup execution
datadir        
    chaindata   # link to fast disk
    snapshots   
        domain    # link to fast disk
        history   
        idx       
        accessors 
    temp   

# Example: how to speedup history access: 
#   - go step-by-step - first try store `accessors` on fast disk
#   - if speed is not good enough: `idx`
#   - if still not enough: `history` 

# eth-mainnet - archive - April 2024

du -hsc /erigon/* 
6G  	/erigon/caplin
50G 	/erigon/chaindata
1.8T	/erigon/snapshots
1.9T	total

du -hsc /erigon/snapshots/* 
100G 	/erigon/snapshots/accessor
240G	/erigon/snapshots/domain
260G	/erigon/snapshots/history
410G	/erigon/snapshots/idx
1.7T	/erigon/snapshots

# bor-mainnet - archive - Jun 2024

du -hsc /erigon/* 

160M	/erigon/bor
50G 	/erigon/chaindata
3.7T	/erigon/snapshots
3.8T	total

du -hsc /erigon/snapshots/* 
260G	/erigon-data/snapshots/accessor
850G	/erigon-data/snapshots/domain
650G	/erigon-data/snapshots/history
1.4T	/erigon-data/snapshots/idx
4.1T	/erigon/snapshots

• --sync.loop.block.limit=10_000 --batchSize=2g - likely will help for sync speed.
• on cloud-drives (good throughput, bad latency) - can enable OS's brain to pre-fetch: SNAPSHOT_MADV_RND=false
• can lock latest state in RAM - to prevent from eviction (node may face high historical RPC traffic without impacting Chain-Tip perf):

vmtouch -vdlw /mnt/erigon/snapshots/domain/*bt
ls /mnt/erigon/snapshots/domain/*.kv | parallel vmtouch -vdlw

# if it failing with "can't allocate memory", try: 
sync && sudo sysctl vm.drop_caches=3
echo 1 > /proc/sys/vm/compact_memory