by When deploying a Nutanix Community Edition cluster, ensuring your SSDs and HDDs are assigned to the correct storage tiers is essential for optimal performance. Occasionally, Nutanix CE may misclassify SSDs as HDDs, leading to performance issues. This blog post provides a step-by-step guide to verify and correct disk tiering for your cluster.
Why Does Disk Tiering Matter?
Nutanix uses a two-tier storage system:
- SSD Tier: High-performance tier for hot data.
- HDD Tier: High-capacity tier for colder data.
If SSDs are misclassified as HDDs, your cluster might not perform as expected, particularly under workloads requiring fast I/O.
Step-by-Step Guide to Verify and Correct Disk Tiering
Step 1: Login to a CVM
Access any one of your Nutanix CVMs (Controller Virtual Machines) via SSH. Use the same credentials you configured during the setup process.
ssh nutanix@<CVM_IP>
Step 2: List the Disks
Run the following command on the CVM to list all the disks and their current tier assignments:
ncli disk ls
This command retrieves information about all the disks across the cluster. Look for the Tier column to identify the assigned tier (e.g., SSD-SATA, HDD-SATA).
Step 3: Verify Disk Tier Assignments
Inspect the output to ensure that SSDs are assigned to the SSD-SATA tier and HDDs to the HDD-SATA tier.
Step 4: Update Incorrect Tier Assignments
If an SSD is assigned to the wrong tier, use the following command to update it:
ncli disk update id=<DISK_ID> tier-name=SSD-SATA
- Replace
<DISK_ID>with the actual disk ID from thencli disk lsoutput. Example:
ncli disk update id=000629bb-d9f9-10d0-0711-246e963cb590::48 tier-name=SSD-SATA
Step 5: Verify the Changes
After making the changes, run the ncli disk ls command again to confirm that the disk is now assigned to the correct tier.
ncli disk ls
Step 6: Verify in the Prism Element GUI
You can also verify the tier assignments through the Prism Element web GUI:
- Log in to Prism Element.
- Navigate to Hardware > Disks.
- Check the tier assignments for each disk.
Conclusion
Verifying and correcting disk tiering is a critical step in ensuring the performance and reliability of your Nutanix CE cluster. By following the steps outlined above, you can ensure that your SSDs are properly assigned to the SSD tier and that your cluster operates at peak efficiency.