Chapter 26. Extending a Stratis volume with additional block devices
You can attach additional block devices to a Stratis pool to provide more storage capacity for Stratis file systems.
Stratis is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process. For more information about the support scope of Red Hat Technology Preview features, see https://access.redhat.com/support/offerings/techpreview.
26.1. Components of a Stratis volume
Learn about the components that comprise a Stratis volume.
Externally, Stratis presents the following volume components in the command-line interface and the API:
blockdev- Block devices, such as a disk or a disk partition.
poolComposed of one or more block devices.
A pool has a fixed total size, equal to the size of the block devices.
The pool contains most Stratis layers, such as the non-volatile data cache using the
dm-cachetarget.Stratis creates a
/dev/stratis/my-pool/directory for each pool. This directory contains links to devices that represent Stratis file systems in the pool.
filesystemEach pool can contain one or more file systems, which store files.
File systems are thinly provisioned and do not have a fixed total size. The actual size of a file system grows with the data stored on it. If the size of the data approaches the virtual size of the file system, Stratis grows the thin volume and the file system automatically.
The file systems are formatted with XFS.
ImportantStratis tracks information about file systems created using Stratis that XFS is not aware of, and changes made using XFS do not automatically create updates in Stratis. Users must not reformat or reconfigure XFS file systems that are managed by Stratis.
Stratis creates links to file systems at the
/dev/stratis/my-pool/my-fspath.
Stratis uses many Device Mapper devices, which show up in dmsetup listings and the /proc/partitions file. Similarly, the lsblk command output reflects the internal workings and layers of Stratis.
26.2. Adding block devices to a Stratis pool
This procedure adds one or more block devices to a Stratis pool to be usable by Stratis file systems.
Prerequisites
- Stratis is installed. See Installing Stratis.
-
The
stratisdservice is running. - The block devices that you are adding to the Stratis pool are not in use and not mounted.
- The block devices that you are adding to the Stratis pool are at least 1 GiB in size each.
Procedure
To add one or more block devices to the pool, use:
# stratis pool add-data my-pool device-1 device-2 device-n
Additional resources
-
stratis(8)man page on your system
26.3. Adding a block device to a Stratis pool by using the web console
You can use the web console to add a block device to an existing Stratis pool. You can also add caches as a block device.
Prerequisites
You have installed the RHEL 8 web console.
For instructions, see Installing and enabling the web console.
-
The
stratisdservice is running. - A Stratis pool is created.
- The block devices on which you are creating a Stratis pool are not in use and are not mounted.
- Each block device on which you are creating a Stratis pool is at least 1 GB.
Procedure
Log in to the RHEL 8 web console.
For details, see Logging in to the web console.
- Click .
- In the Storage table, click the Stratis pool to which you want to add a block device.
On the Stratis pool page, click .
In the Add block devices dialog box, select the Tier, whether you want to add a block device as data or cache.
- Optional: If you are adding the block device to a Stratis pool that is encrypted with a passphrase, then you must enter the passphrase.
- Under Block devices, select the devices you want to add to the pool.
- Click .
