Backup Tool

1. Overview

The IoTDB Full Backup Tool is designed to create a full backup of a single IoTDB node’s data via hard links to a specified local directory. The backup can then be directly started and joined to the original cluster. The tool offers two modes: Quick Mirror Mode and Manual Backup Path Mode.

Notes:

• Stop the IoTDB service before starting the backup.
• The script runs in the background by default, and logs are saved to log files during execution.

2. Backup Modes

2.1 Mode 1: Quick Mirror Mode

Usage

backup.sh/backup.bat -quick -node xxx 
# Optional values for xxx are shown in the following examples

backup.sh/backup.bat -quick -node 
# Back up all nodes to the default path 

backup.sh/backup.bat -quick -node all 
# Back up all nodes to the default path 

backup.sh/backup.bat -quick -node confignode 
# Back up only the ConfigNode to the default path 

backup.sh/backup.bat -quick -node datanode 
# Back up only the DataNode to the default path

Parameter Descriptions

Parameter	Description	Required
-quick	Enables Quick Mirror Mode.	No
-node	Specifies the node type to back up. Options: all, datanode, or confignode. Default: all. all: Back up both DataNode and ConfigNode. datanode: Back up only the DataNode. confignode: Back up only the ConfigNode.	No

Process Details:

1. Check if the _backup folder already exists in the current IoTDB directory or paths specified in the configuration file. If it exists, the tool exits with the error: The backup folder already exists.

When the backup folder already exists, you can try the following solutions:

• Delete the existing _backup folder and retry the backup.
• Modify the backup path to avoid conflicts.

2. Create hard links from the original dn_data_dirs paths to the corresponding _backup paths.
   • Example: If dn_data_dirs=/data/iotdb/data/datanode/data, the backup data will be stored in /data/iotdb/data/datanode/data_backup.
3. Copy other files from the IoTDB directory (e.g., /data/iotdb) to the _backup path (e.g., /data/iotdb_backup).

2.2 Mode 2: Manual Backup Path Mode

Usage

backup.sh -node xxx -targetdir xxx -targetdatadir xxx -targetwaldir xxx

Parameter Descriptions

Parameter	Description	Required
-node	Node type to back up (all, datanode, or confignode). Default: all.	No
-targetdir	Target directory for backing up the IoTDB folder.	Yes
-targetdatadir	Target path for dn_data_dirs files. Default: targetdir/data/datanode/data.	No
-targetwaldir	Target path for dn_wal_dirs files. Default: targetdir/data/datanode/wal.	No

Process Details:

1. The -targetdir parameter is mandatory. If missing, the tool exits with the error: -targetdir cannot be empty. The backup folder must be specified.

2. Validate consistency between configuration paths (dn_data_dirs, dn_wal_dirs) and parameters (-targetdatadir, -targetwaldir):

   • If -targetdatadir or -targetwaldir is a single path, it is considered consistent.
   • If the number of source paths (from configuration) does not match the target paths, the tool exits with the error: -targetdatadir parameter exception: the number of original paths does not match the specified paths.

3. Check if -targetdatadir paths are on the same disk as the original paths:

   • Same disk: Attempt to create hard links. If hard links fail, copy files instead.
   • Different disk: Copy files directly.

4. Path Matching Rules

• Many-to-One: Multiple source paths can be backed up to a single target path.
• One-to-One: A single source path can be backed up to a single target path.
• Many-to-Many: Multiple source paths can be backed up to multiple target paths, but the pattern must match.

Examples

Configuration Paths	-targetdatadir Paths	Result
/data/iotdb/data/datanode/data	/data/iotdb_backup/data/datanode/data	Consistent
/data/iotdb/data/datanode/data	/data/iotdb_backup/data/datanode/data1,/data/iotdb_backup/data/datanode/data2	Inconsistent
/data/iotdb/data/datanode/data1,/data/iotdb/data/datanode/data2	/data/iotdb_backup/data/datanode/data	Consistent
/data/iotdb/data/datanode/data1,/data/iotdb/data/datanode/data2	/data/iotdb_backup/data/datanode/data3,/data/iotdb_backup/data/datanode/data4	Consistent
/data/iotdb/data/datanode/data1,/data/iotdb/data/datanode/data2;/data/iotdb/data/datanode/data3	/data/iotdb_backup/data/datanode/data	Consistent
/data/iotdb/data/datanode/data1,/data/iotdb/data/datanode/data2;/data/iotdb/data/datanode/data3	/data/iotdb_backup/data/datanode/data1;/data/iotdb_backup/data/datanode/data1	Consistent
/data/iotdb/data/datanode/data1,/data/iotdb/data/datanode/data2;/data/iotdb/data/datanode/data3	/data/iotdb_backup/data/datanode/data1,/data/iotdb_backup/data/datanode/data3;/data/iotdb_backup/data/datanode/data	Consistent
/data/iotdb/data/datanode/data1,/data/iotdb/data/datanode/data2;/data/iotdb/data/datanode/data3	/data/iotdb_backup/data/datanode/data1,/data/iotdb_backup/data/datanode/data3;/data/iotdb_backup/data/datanode/data1,/data/iotdb_backup/data/datanode/data4	Inconsistent

Path Matching Rules Summary

• Paths separated by ; only:
  • -targetdatadir can be a single path (no ; or ,).
  • -targetdatadir can also use ; to split paths, but the count must match the source paths.
• Paths separated by , only:
  • -targetdatadir can be a single path (no ; or ,).
  • -targetdatadir can also use , to split paths, but the count must match the source paths.
• Paths with both ; and ,:
  • -targetdatadir can be a single path (no ; or ,).
  • Split paths first by ;, then by ,. The number of paths at each level must match.

Note: The dn_wal_dirs parameter (for WAL paths) follows the same rules as dn_data_dirs.