Set up the SnapTool external snapshots manager

The SnapTool is an external snapshots manager that enables scheduled snapshots and automatic operations

WEKA provides an external snapshots manager called SnapTool, allowing you to efficiently schedule and manage filesystem snapshots for your WEKA cluster.

Key features of SnapTool include:

• Schedule snapshots at monthly, daily, or minute-level intervals throughout the day.

• Set the number of snapshot copies to retain for each schedule.

• Automatically delete expired snapshots.

• Automatically upload snapshots of a filesystem to its configured object store.

• Perform uploads and deletions in the background.

• Access a Web Status GUI to view snapshot schedules, upload/download queues, locator IDs for uploaded snapshots, and logs. The default URL is http://<snaptool server hostname/IP>:8090.

Configuration of SnapTool is managed by editing the snaptool.yml file before installation. To adjust SnapTool’s behavior after installation, update this file. SnapTool automatically monitors the configuration file and reloads it approximately every minute when changes are detected.

SnapTool installation and communication with WEKA cluster

The SnapTool runs on any Linux-based physical server or VM, communicating with the WEKA cluster via an IP connection to a WEKA host using the WEKA REST API. It can be installed as a systemd service or within a Docker container.

SnapTool setup

If you have deployed the WMS, follow the procedure in:Deploy monitoring tools using the WEKA Management Station (WMS). Otherwise, continue with this workflow.

Before you begin

If a previous SnapTool version exists in the physical server, make a copy of your existing snaptool.yml file.

If the snaptool.yml file is from releases before 1.0.0, it is incompatible with 1.0.0 or higher. You need to modify the file to use the new syntax.

Setting up a dedicated physical server (or VM) for the installation is recommended.

Server minimum requirements

• 2 cores

• 8 GB RAM

• 5 GB /opt/ partition (for the SnapTool installation)

• Network access to the WEKA cluster

• To use Docker, the following must be installed on the dedicated physical server (or VM):

  • docker-ce

  • docker-compose or docker-compose-plugin, depending on the existing operating system.

  For instructions on the Docker installation, see the Docker website.

SnapTool authentication

For the SnapTool host to communicate with the WEKA cluster, a security token is necessary. However, the SnapTool host is not required to have the WEKA client installed.

Prepare SnapTool user and token

Perform the following steps on an existing host with access to the WEKA CLI, for example, on a WEKA backend server.

1. Create a dedicated user: Create a unique local username (for example, snaptool) for SnapTool. The unique username is displayed in the event logs, making the identification and troubleshooting of issues easier. Then, assign the ClusterAdmin or OrgAdmin role. Example: weka user add snaptool clusteradmin

2. Generate an authentication token for the user: Run the following command: weka user login snaptool --path snaptool-authtoken.json

3. Transfer the token: Copy the snaptool-authtoken.json file to the SnapTool management server. It will later be placed in a specific directory on that host.

4. Remove the token file: Delete the snaptool-authtoken.json locally. Example: rm snaptool-authtoken.json

Configure SnapTool host with authentication token

Perform the following steps on the SnapTool host.

1. Create a directory for the authentication token: Run the following command:

   mkdir /root/.weka

2. Move the previously-created authentication token into the new directory: : Run the following command: mv ~/snaptool-authtoken.json /root/.weka/auth-token.json

3. Ensure appropriate ownership and permissions are set: Run the following commands: chown root:root /root/.weka/auth-token.json chmod 400 /root/.weka/auth-token.json

Related topics

Create a local user

Obtain authentication tokens

Option 1: Install the SnapTool package with the systemd service

1. Download the latest snaptool.tar file from this link and extract it to the physical server.

2. Edit the snaptool.yml configuration file (default location: /opt/weka/snaptool). See Edit the configuration in snaptool.yml. This is a mandatory step before running the installer. Otherwise, the installation fails.

3. Install the unit file into the systemd and start the service. Run the following command: ./install.sh The installer validates the connection to the cluster by the hosts specified in the snaptool.yml file.

If the systemd service is already running locally, the installer stops it and preserves the existing snaptool.yml file before restarting it.

Option 2: Install the SnapTool package in Docker

The snaptool container runs similarly to other WEKA Docker containers.

1. Download the docker image from the docker hub. Run the following command: docker pull wekasolutions/snaptool:latest

2. Download the following files from GitHub https://github.com/weka/snaptool/releases to a dedicated directory in the physical server:

   • snaptool.yml

   • docker_run.sh

3. Edit the snaptool.yml configuration file (default location: /opt/weka/snaptool). See Edit the configuration in snaptool.yml. This is a mandatory step before running the installer. Otherwise, the installation fails.

4. Edit the time_zone field in the docker_run.sh file.

5. Run the following command: ./docker_run.sh

6. Verify that the SnapTool container is running using the following command: docker ps

Example:

oot@weka142:~# docker ps
CONTAINER ID   IMAGE                   COMMAND                 CREATED      STATUS     PORTS   NAMES
718486e75b38   wekasolutions/snaptool  "/wekabin/snaptool -…"  30 hours ago Up 5 hours         weka_snaptool

A logs directory is created during the installation in the current working directory for logs and snapshot journaling files.

Edit the configuration in the snaptool.yml file

The SnapTool configuration is defined in the snaptool.yml file.

1. Go to the snaptool directory and open the snaptool.yml file.

2. In the cluster section under the hosts list, replace the hostnames with the actual hostnames/IP addresses of the Weka containers (up to three would be sufficient).

Syntax:

cluster:
    auth_token_file: auth-token.json
    hosts: vweka01,vweka02,vweka03

Example:

cluster:
    auth_token_file: auth-token.json
    hosts: hostname1,hostname2,hostname3

3. In the snaptool section, the default network port to access the Web Status GUI is 8090. If required, you can modify it. To disable the Web Status GUI, set the port to 0.

Syntax:

snaptool:
    port: 8090

4. In the filesystems section, specify the filesystems and their schedule names to run snapshots.

Syntax:

<fs_name1>:  <schedule1>,<schedule2>...
<fs_name2>:  <schedule1>,<schedule2>...

Example:

filesystems:
   fs01: default
   fs02: Weekdays-6pm, Weekends-noon

5. Optional. Customize the snapshot schedules.

Adhere to the following rules when customizing the schedules:

• Schedules within a schedules group, such as default, cannot be assigned separately from the group. Use only the group name.

• To set a specific schedule within a schedules group, such as monthly and weekly, not to run on a filesystem, remove it from the filesystem's schedule list.

• When deleting snapshots automatically, based on the retain: value, snapshots for a schedule and filesystem are sorted by the creation time. The oldest snapshots are deleted until the number of snapshots to retain (the value specified in the retain: section) remains.

• The SnapTool checks if the snaptool.yml file has changed about every minute and reloads it if it is changed. Snapshot schedules are then recalculated before creating new snapshots.

For details about the syntax of the schedules section, see the comments in the snaptool.yml file.

Example:

schedules:
   default:
      monthly:
         every: month
         retain: 6
         # day: 1   (this is default)
         # at: 0000 (this is default)
      weekly:
         every: Sunday
         retain: 8
         # at: 0000 (this is default)
      daily:
         every: Mon,Tue,Wed,Thu,Fri,Sat
         retain: 14
         # at: 0000 (this is default)
      hourly:
         every: Mon,Tue,Wed,Thu,Fri
         retain: 8
         interval: 60
         at: 9:00am
         until: 5pm
   workhoursHourlyUp:
      every: Mon,Tue,Wed,Thu,Fri
      retain: 7
      at: 0900
      until: 5pm
      interval: 60
      upload: True
   workhoursEvery20:
      every: Mon,Tue,Wed,Thu,Fri
      retain: 7
      at: 0900
      until: 5pm
      interval: 20
   weekendsNoon:
      every: Sat,Sun
      retain: 4
      at: 1200
   fridayUpload:
      every: Friday
      retain: 3
      at: 7pm
      upload: True

Snapshot naming conventions

The format of the snapshot names is <schedulename>.YYMMDDHHMM, with the access point @GMT-YYYY.MM.DD-HH.MM.SS.

Example: For a snapshot name Weekends-noon.2103101200 and access point @GMT-2021.03.10-12.00.00, the snapshot name is in the local timezone, the access point is in GMT, and the server timezone is GMT.

The name for a group of snapshots is<schedulegroupname>_<schedulename>.YYMMDDHHMM. The length of the full name before the '.' is a maximum of 18 characters.

Example: The default schedule group with an hourly schedule can be named default_hourly.YYMMDDHHMM.

The SnapTool distinguishes between user-created snapshots and scheduled snapshots only by their name.

When creating user-created snapshots, avoid name collisions with scheduled snapshot names. The SnapTool might automatically select the user-created snapshots for deletion if the same naming format is used.

Modify SnapTool schedules

To change, add, or remove schedules in the SnapTool configuration after installation, follow these steps:

1. Edit the configuration file: Open the snaptool.yml file, typically located at /opt/weka/snaptool/snaptool.yml, and make the necessary changes, such as adjusting schedules or adding filesystems. See Edit the configuration in the snaptool.yml file.

2. Save changes: Save the modified snaptool.yml file after making the updates.

3. Automatic reload: SnapTool checks for changes in the configuration file approximately every minute and automatically reloads it if any changes are detected.

4. Manually apply changes (optional): If you want to apply the changes immediately, restart the SnapTool service with the following command:

   sudo systemctl restart weka-snaptool.service

5. Verify changes: Review the SnapTool logs in the logs directory or monitor snapshot schedules to ensure the new configuration is applied. (The logs directory is created during installation in the current working directory for logs and snapshot journaling files.)

Check snapshot status and rotation

To check if snapshots are running and rotating in a WEKA system, use the following commands:

• View snapshots: Run weka fs snapshot to list all available snapshots, including their creation time and status.

• View snapshot details: For details on a specific snapshot, use weka fs snapshot --name <snapshot-name>.

• Check snapshot rotation: Regularly review the list and timestamps to ensure old snapshots are being deleted and new ones are created as per the snapshot policy.

For more information on checking snapshot status and rotation, see Snapshots.