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:

• fall back to the data state of a desired block height instantly
• the atomicity of snapshot data can be guaranteed
• 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(0), true).unwrap(); ```

Binary Usages

Usage of btm ...:

```shell btm

USAGE: btm [FLAGS] [OPTIONS] [SUBCOMMAND]

FLAGS: -h, --help Prints help information -C, --snapshot-clean clean up all existing snapshots -l, --snapshot-list list all available snapshots in the form of block height -x, --snapshot-rollback rollback to the last available snapshot -V, --version Prints version information

OPTIONS: -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 <Height>
        rollback to a custom height exactly, an error will be reported if the target does not exist

-p, --snapshot-target <TargetPath>           a data volume containing both ledger data and tendermint data

SUBCOMMANDS: daemon help Prints this message or the help of the given subcommand(s) ```

Usage of btm daemon ...:

```shell btm-daemon

USAGE: btm daemon [OPTIONS]

FLAGS: -h, --help Prints help information -V, --version Prints version information

OPTIONS: -a, --snapshot-algo fair/fade, default to fair -c, --snapshot-cap the maximum number of snapshots that will be stored, default to 100 -i, --snapshot-itv interval between adjacent snapshots, default to 10 blocks -m, --snapshot-mode zfs/btrfs/external, will try a guess if missing -p, --snapshot-target a data volume containing both ledger data and tendermint 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-target=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-target=<TARGET>

Example

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

Example, short style

install.sh -i=4 -c=100 -m=zfs -a=fade -t=zfs/data

```