BTM

Blockchain Time Machine.

BTM is an incremental data backup mechanism that does not require downtime.

Why would you need this?

btm will give you the following abilities or advantages:

• rollback to the state of a desired block height
• hot backup during operation, no downtime is needed
• based on OS-level infrastructure, stable and reliable
• very small resource usage, almost no performance damage
• ...

Library Usages

```rust use btm::{BtmCfg, SnapMode, SnapAlgo};

let cfg = BtmCfg { enable: true, itv: 10, cap: 100, mode: SnapMode::Zfs, algo: SnapAlgo::Fade, volume: "zroot/data".to_owned(), };

// Generate snapshots in some threads. cfg.snapshot(0).unwrap(); cfg.snapshot(1).unwrap(); cfg.snapshot(11).unwrap();

/// Print all existing snapshots. cfg.list_snapshots();

/// Rollback to the state of the last snapshot. cfg.rollback(None, false).unwrap();

/// Rollback to the state of a custom snapshot. cfg.rollback(Some(11), true).unwrap(); ```

Binary Usages

Usage of btm ...:

```shell Usage: btm [OPTIONS] [COMMAND]

Commands: daemon help Print this message or the help of the given subcommand(s)

Options: -p, --snapshot-volume [] a data volume containing your blockchain data -l, --snapshot-list list all available snapshots in the form of block height -x, --snapshot-rollback rollback to the last available snapshot -r, --snapshot-rollback-to [] rollback to a custom height, will try the closest smaller height if the target does not exist -R, --snapshot-rollback-to-exact [] rollback to a custom height exactly, an error will be reported if the target does not exist -C, --snapshot-clean clean up all existing snapshots -K, --snapshot-clean-kept [] clean up old snapshots out of kept capacity -h, --help Print help information -V, --version Print version information ```

Usage of btm daemon ...:

```shell Usage: btm daemon [OPTIONS]

Options: -p, --snapshot-volume [] a data volume containing your blockchain data -i, --snapshot-itv [] interval between adjacent snapshots, default to 10 blocks -c, --snapshot-cap [] the maximum number of snapshots that will be stored, default to 100 -m, --snapshot-mode [] zfs/btrfs/external, will try a guess if missing -a, --snapshot-algo [] fair/fade, default to fair -h, --help Print help information ```

Install as a 'systemd service'

Steps:

```shell make mv btmpackage.tar.gz /tmp/ cd /tmp/ tar -xpf btmpackage.tar.gz cd btm_package

su # swith your user account to 'root'

./install.sh \ --snapshot-itv=4 \ --snapshot-cap=100 \ --snapshot-mode=zfs \ --snapshot-algo=fade \ --snapshot-volume=zfs/data ```

Outputs of systemctl status btm-daemon.service:

shell ● btm-daemon.service - "btm daemon" Loaded: loaded (/lib/systemd/system/btm-daemon.service; enabled; vendor preset: disabled) Active: active (running) since Tue 2021-10-12 21:24:16 CST; 2min 27s ago Main PID: 334 (btm) Tasks: 1 (limit: 37805) CPU: 1ms CGroup: /system.slice/btm-daemon.service └─334 /usr/local/bin/btm daemon -p=/data -i=4 -c=100 -m=btrfs -a=fade

Usage of tools/install.sh:

```shell

tools/install.sh -h

Usage

install.sh
    --snapshot-itv=<ITV>
    --snapshot-cap=<CAP>
    --snapshot-mode=<MODE>
    --snapshot-algo=<ALGO>
    --snapshot-volume=<VOLUME>

Example

install.sh \
    --snapshot-itv=4 \
    --snapshot-cap=100 \
    --snapshot-mode=zfs \
    --snapshot-algo=fair \
    --snapshot-volume=zfs/blockchain

Example, short style

install.sh -i=4 -c=100 -m=zfs -a=fair -p=zfs/blockchain
install.sh -i=4 -c=100 -m=btrfs -a=fair -p=/data/blockchain

```