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 btm

USAGE: btm [OPTIONS] [SUBCOMMAND]

OPTIONS: -C, --snapshot-clean clean up all existing snapshots

-h, --help
        Print help information

-K, --snapshot-clean-kept [<KeptNum>...]
        clean up old snapshots out of kept capacity

-l, --snapshot-list
        list all available snapshots in the form of block height

-p, --snapshot-volume [<VolumePath>...]
        a data volume containing your blockchain data

-r, --snapshot-rollback-to [<Height>...]
        rollback to a custom height, will try the closest smaller height if the target does not
        exist

-R, --snapshot-rollback-to-exact [<Height>...]
        rollback to a custom height exactly, an error will be reported if the target does not
        exist

-x, --snapshot-rollback
        rollback to the last available snapshot

```

Usage of btm daemon ...:

```shell btm-daemon

USAGE: btm daemon [OPTIONS]

OPTIONS: -a, --snapshot-algo [...] fair/fade, default to fair

-c, --snapshot-cap [<Capacity>...]
        the maximum number of snapshots that will be stored, default to 100

-h, --help
        Print help information

-i, --snapshot-itv [<Iterval>...]
        interval between adjacent snapshots, default to 10 blocks

-m, --snapshot-mode [<Mode>...]
        zfs/btrfs/external, will try a guess if missing

-p, --snapshot-volume [<VolumePath>...]
        a data volume containing your blockchain data

```

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

```