Install

Installing flexBlock means placing one static binary on the host, installing the grant Paradigm4 issued for your volume, and making sure the host can reach the bucket.

Before you begin, check the Requirements. You need:

• Linux 6.1 or newer, with ublk_drv loadable, and root.
• A cache device: a local NVMe drive or partition.
• A bucket and prefix in object storage, the prefix empty.
• Your grant file, signed by Paradigm4, naming both.

1. Install the binary

   Paradigm4 delivers flexblock as a statically linked executable for x86_64 and aarch64. Copy the one for your architecture into the path, load the ublk module, and confirm the binary runs.

   sudo install -m 0755 flexblock /usr/local/bin/flexblock
   sudo modprobe ublk_drv
   flexblock --version
   flexblock --help

   To load ublk_drv at every boot, list it in a modules-load file. The systemd unit also loads it before each start; see Running Under systemd.

   echo ublk_drv | sudo tee /etc/modules-load.d/flexblock.conf

2. Install the license grant

   Your grant is a small JSON file signed by Paradigm4. It is specific to one bucket and prefix, and every flexblock command on every host that will serve the volume needs a copy. Install it where flexblock looks by default:

   sudo install -D -m 0644 grant.json /etc/flexblock/grant.json

   Or keep it elsewhere and point at it with the global --grant-file flag. The grant contains no secrets and no object-storage credentials; it identifies the volume and the terms under which it may be served. See Licensing.

3. Configure credentials

   Configure your object storage credentials as usual, for example an instance role or principal, a credentials file, or environment variables. FlexBlock never takes credentials on the command line. See Credentials.

4. Verify the grant and credentials

   Check that the grant and your credentials agree before touching any device:

   sudo -E flexblock show --remote

   show --remote uses only read and list. init, attach and start also check write, overwrite and delete before they change anything.

One grant, one volume

Because the grant names the bucket and prefix, a host that serves several volumes keeps several grant files and passes --grant-file to choose between them. The systemd template in Running Under systemd shows one way to organize this.

Tip

Use sudo -E when your credentials are exported as environment variables, so they survive sudo. With a platform identity such as an instance role, plain sudo is enough.

A permission problem surfaces as a permanent storage error naming the provider, the operation and the HTTP status, for example gcs LIST flexblock/acme-0001/ [403], and the command exits with code 14.

Other ways to run flexBlock

• Container image. FlexBlock can also run from its runtime container image. See Container Image.
• Without NVMe or a cloud bucket. For a trial, a regular file can stand in for the cache device and a local emulator for the bucket. See Evaluating Without Hardware.

Next steps

• Credentials: what the identity needs, per provider.
• Your First Volume: create, serve, mount and stop a volume.