1  ---
 2  tags:
 3    - codex/block-storage
 4  related:
 5    - "[[Uploading and downloading content in Codex]]"
 6    - "[[Codex Blocks]]"
 7    - "[[Codex Block Exchange Protocol]]"
 8  ---
 9  #codex/block-storage
10  
11  | related | [[Uploading and downloading content in Codex]], [[Codex Blocks]], [[Codex Block Exchange Protocol]] |
12  | ------- | --------------------------------------------------------------------------------------------------- |
13  
14  To store blocks and the corresponding metadata, we use `RepoStore`.
15  
16  `RepoStore` is a proxy to two underlying stores:
17  
18  - `repoDS` - to store the blocks themselves - by default it is `FSDatastore` as indicated by option `repoKind` in `CodexConf` (`codex/conf.nim`). Other types of storage are also available: `SQLiteDatastore`, `LevelDbDatastore`.
19  - `metaDS` - to store the blocks' metadata - `LevelDbDatastore` (`vendor/nim-datastore/datastore/leveldb/leveldbds.nim`).
20  
21  The stores are initialized in `CodexServer.new` (`codex/codex.nim`) and injected into `repoStore` (type `RepoStore` defined in `codex/stores/repostore/types.nim`):
22  
23  ```nim
24  repoStore = RepoStore.new(
25    repoDs = repoData,
26    metaDs = LevelDbDatastore.new(config.dataDir / CodexMetaNamespace).expect(
27      "Should create metadata store!"
28    ),
29    quotaMaxBytes = config.storageQuota,
30    blockTtl = config.blockTtl,
31  )
32  ```
33  
34  The default value for `storageQuota` is given by `config.storageQuota` and `config.blockTtl` (`codex/stores/repostore/types.nim`):
35  
36  ```nim
37  const
38    DefaultBlockTtl* = 24.hours
39    DefaultQuotaBytes* = 8.GiBs
40  ```
41  
42  `repoStore` together with `engine` (`BlockExcEngine`) are parts of `NetworkStore`, which together with `switch`, `engine`, `discovery`, and `prover` is then provided to `codexNode` (`CodexNodeRef`).