In our previous guide, we have seen how to install and create Stratis layered storage pool and file systems. Now let us see how to manage Stratis by adding new disks to the existing pool and adding cache disk. By following will cover with removing pools and file system.

Read more about Stratis layered storage:

Adding an additional disk to the pool

It’s super easy to add a new block device to existing pool under Stratis management. In our setup we have 4 disks in “data01_pool”, now we required to extend the space in the pool by adding a new disk. Use the option “add-data” to add a new disk.

# stratis pool list
# stratis pool add-data data01_pool /dev/sdf
Stratis layered storage - Adding an additional disk to the existing pool in Stratis
Adding an additional disk to the existing pool in Stratis
# stratis pool list

In the above figure we can notice before adding a disk its total physical size is “8 TB”, And after adding a “2 TB” disk the size has been extended to “10 TB”.

  1. Listing the existing Stratis pools.
  2. Adding an additional disk to the existing pool.
  3. The device we are about to add to the existing pool.
  4. The total size of the pool after adding a new disk.

Adding a Cache disk to Stratis pool

To improve the performance of storage Stratis provided with an option to add a cache disk. Caching can be configured for redundancy or non-redundancy, write-back and write-through modes. This step will be similar to adding an additional disk by replacing option “add-cache”.

# stratis blockdev list
# fdisk -l /dev/sdg
Stratis layered storage - Adding Cache disk to Stratis pool
Adding Cache disk to Stratis Pool
# stratis pool add-cache data01-pool /dev/sdg
# stratis blockdev list
  1. The existing list of block devices under the pool.
  2. 500 GB Disk we are about to add in the pool.
  3. Adding a cache disk using option “add-cache”.
  4. Added cache disk in the data pool.

Renaming Pools and file systems

Stratis has the feature to rename a pool or filesystem on the fly without impacting any running setup. In case if we need to rename the pool it’s quite easy by running a single command with options and arguments.

Let us rename our current pool name “data01_pool” to “data01_pool_old”.

# stratis pool list
# stratis pool rename data01_pool data01_pool_old
# stratis pool list
Stratis layered storage - Renaming Pools
Renaming Pools
  1. Current Pool name needs to be renamed.
  2. The new name of the pool we are about to rename.
  3. Pool name after renamed.

Let us see how to rename the file System.

Renaming a file system is similar to renaming a pool. Only we need to replace the option “pool” and “filesystem” and make sure to use the correct names of pool and FS if you have multiple numbers in your server.

Stratis layered storage - Renaming filesystem in Stratis
Renaming filesystem in Stratis

Removing a Stratis filesystem

Managing Stratis storage by removing a file system, Initially, we need to remove the fstab entry, by following un-mount the file system.

# vi /etc/fstab
# umount /user_data02

After unmounting the file system, we need to use the correct pool name with the file system which needs to be removed.

# stratis filesystem list
# stratis filesystem destroy data01_pool user_data02
Destroy a file-system from Stratis pool
Destroy a file-system from Stratis pool
  1. Unmount the file system.
  2. List the file systems created using Stratis.
  3. Choose the file system we need to destroy.
  4. Use the “destroy” option with Stratis command.
  5. List to verify the destroyed file system.

Removing a Stratis Pool

To remove a Stratis pool we should remove the file system created under it. In case if we try to remove a pool without destroying the FS it will throw an error similar to below.

[root@linuxsysadmins ~]# stratis pool destroy data01_pool_old 
Execution failure caused by:
BUSY: filesystems remaining on pool

List the available pool and destroy it.

# stratis pool list
# stratis pool destroy data01_pool_old
# stratis pool list
Destroy Pool in Stratis
Destroy Pool in Stratis
  1. List to verify.
  2. Destroy the pool.
  3. Again list to verify the status.

Create a Snapshot in Stratis

Stratis comes with a major required solution to take a snapshot of any file system. Let us take a snapshot of the existing file System in our server.

# stratis filesystem list
# stratis filesystem snapshot data01_pool_old user_data01 user_data01_snapshot
# stratis filesystem list data01_pool_old
Snapshot a filesystem in Stratis
Snapshot a filesystem in Stratis

That’s it, Managing a layered storage system Startis is easy than any other storage management tools.

If you face any issue or interested to contribute to Startis you can reach GITHUB.

Conclusion:

We have seen how to manage Stratis storage by adding disks and renaming them. In our future article will cover with more Stratis topics. Subscribe to our newsletter and give your feedback or query in below comment section.

4 COMMENTS

  1. Great article Babin.

    You have a spelling mistake which you want to correct btw: destory

    # stratis filesystem destory data01_pool user_data02
    should be
    # stratis filesystem destroy data01_pool user_data02

    BTW, when you’re adding a Cache Disk, can you add a Mirrored Caching disks (like in ZFS)?
    This would be important with writeback in case the cache disk dies… could result in dataloss

    Cheers

    • @Zubin,

      Thank you for pointing typo, It’s cleared.

      Unfortunately, no the mirrored caching options is not available in current version, May be we can expect more features in up-coming releases.

      Thanks & Regards,
      Babin Lonston

    • @David, For time being Stratis not came up with those feature than listed above, Soon they will bring more added features. Will update the articles once we get one.

      Thanks & Regards,
      Babin Lonston

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