3. All content of the data directory, except for `dash.conf` file, is chain-specific. This means the actual data directory paths for non-mainnet cases differ:
`chainstate/` | LevelDB database | Blockchain state (a compact representation of all currently unspent transaction outputs (UTXOs) and metadata about the transactions they are from)
`indexes/blockfilter/basic/db/` | LevelDB database | Blockfilter index LevelDB database for the basic filtertype; *optional*, used if `-blockfilterindex=basic`
`indexes/blockfilter/basic/` | `fltrNNNNN.dat`<sup>[\[2\]](#note2)</sup> | Blockfilter index filters for the basic filtertype; *optional*, used if `-blockfilterindex=basic`
`wallets/` | | [Contains wallets](#multi-wallet-environment); can be specified by `-walletdir` option; if `wallets/` subdirectory does not exist, wallets reside in the [data directory](#data-directory-location)
`./` | `anchors.dat` | Anchor IP address database, created on shutdown and deleted at startup. Anchors are last known outgoing block-relay-only peers that are tried to re-connect to on startup
`./` | `dash.conf` | User-defined [configuration settings](dash-conf.md) for `dashd` or `dash-qt`. File is not written to by the software and must be created manually. Path can be specified by `-conf` option
`./` | `dashd.pid` | Stores the process ID (PID) of `dashd` or `dash-qt` while running; created at start and deleted on shutdown; can be specified by `-pid` option
`./` | `debug.log` | Contains debug information and general logging generated by `dashd` or `dash-qt`; can be specified by `-debuglogfile` option
`./` | `governance.dat` | stores data for governance objects
`./` | `mncache.dat` | stores data for masternode list
`./` | `netfulfilled.dat` | stores data about recently made network requests
`./` | `fee_estimates.dat` | Stores statistics used to estimate minimum transaction fees and priorities required for confirmation
`./` | `guisettings.ini.bak` | Backup of former [GUI settings](#gui-settings) after `-resetguisettings` option is used
`./` | `ip_asn.map` | IP addresses to Autonomous System Numbers (ASNs) mapping used for bucketing of the peers; path can be specified with the `-asmap` option
`./` | `i2p_private_key` | Private key that corresponds to our I2P address. When `-i2psam=` is specified the contents of this file is used to identify ourselves for making outgoing connections to I2P peers and possibly accepting incoming ones. Automatically generated if it does not exist.
`./` | `settings.json` | Read-write settings set through GUI or RPC interfaces, augmenting manual settings from [dash.conf](dash-conf.md). File is created automatically if read-write settings storage is not disabled with `-nosettings` option. Path can be specified with `-settings` option
4.`wallet.dat` files must not be shared across different node instances, as that can result in key-reuse and double-spends due the lack of synchronization between instances.
5. Any copy or backup of the wallet should be done through a `backupwallet` call in order to update and lock the wallet, preventing any file corruption caused by updates during the copy.
`database/` | BDB logging files | Part of BDB environment; created at start and deleted on shutdown; a user *must keep it as safe* as personal wallet `wallet.dat`
`./` | `db.log` | BDB error file
`./` | `wallet.dat` | Personal wallet (a BDB database) with keys and transactions
`./` | `wallet.dat` | Personal wallet (a SQLite database) with keys and transactions
`./` | `wallet.dat-journal` | SQLite Rollback Journal file for `wallet.dat`. Usually created at start and deleted on shutdown. A user *must keep it as safe* as the `wallet.dat` file.
`dash-qt` uses [`QSettings`](https://doc.qt.io/qt-5/qsettings.html) class; this implies platform-specific [locations where application settings are stored](https://doc.qt.io/qt-5/qsettings.html#locations-where-application-settings-are-stored).
`banlist.dat` | Stores the addresses/subnets of banned nodes; completely ignored and superseded by `banlist.json` in 20.0 | [PR #5574](https://github.com/dashpay/dash/pull/5574)
`blktree/` | Blockchain index; replaced by `blocks/index/` in [0.8.0](https://github.com/dash/dash/blob/master/doc/release-notes/release-notes-0.8.0.md#improvements) | [PR #2231](https://github.com/dash/dash/pull/2231), [`8fdc94cc`](https://github.com/dash/dash/commit/8fdc94cc8f0341e96b1edb3a5b56811c0b20bd15)
`coins/` | Unspent transaction output database; replaced by `chainstate/` in 0.8.0 | [PR #2231](https://github.com/dash/dash/pull/2231), [`8fdc94cc`](https://github.com/dash/dash/commit/8fdc94cc8f0341e96b1edb3a5b56811c0b20bd15)
`blkindex.dat` | Blockchain index BDB database; replaced by {`chainstate/`, `blocks/index/`, `blocks/revNNNNN.dat`<sup>[\[2\]](#note2)</sup>} in 0.8.0 | [PR #1677](https://github.com/dash/dash/pull/1677)
`blk000?.dat` | Block data (custom format, 2 GiB per file); replaced by `blocks/blkNNNNN.dat`<sup>[\[2\]](#note2)</sup> in 0.8.0 | [PR #1677](https://github.com/dash/dash/pull/1677)
`addr.dat` | Peer IP address BDB database; replaced by `peers.dat` in [0.7.0](https://github.com/dash/dash/blob/master/doc/release-notes/release-notes-0.7.0.md) | [PR #1198](https://github.com/dash/dash/pull/1198), [`928d3a01`](https://github.com/dash/dash/commit/928d3a011cc66c7f907c4d053f674ea77dc611cc)
