Wouldn’t it be amazing if we didn’t have to waste so much precious space on our expensive and sensitive SSDs to run an Ethereum node, and could rather move at least some of the data onto a cheap and durable HDD?

With the v1.9.0 release, Geth separated its database into two parts (done by Péter Szilágyi, Martin Holst Swende and Gary Rong):

• Recent blocks, all state and accelerations structures are kept in a fast key-value store (LevelDB) as until now. This is meant to be run on top of an SSD as both disk IO performance is crucial.
• Blocks and receipts that are older than a cutoff threshold (3 epochs) are moved out of LevelDB into a custom freezer database, that is backed by a handful of append-only flat files. Since the node rarely needs to read these data, and only ever appends to them, an HDD should be more than suitable to cover it.

A fresh fast sync at block 7.77M placed 79GB of data into the freezer and 60GB of data into LevelDB. Weiterlesen