PowerFlex: Volumes are Read Only if MDM Cluster has no Tie Breaker

Summary: If only one MDM and no tie-breaker is available, the volume goes into read-only mode.

This article applies to This article does not apply to This article is not tied to any specific product. Not all product versions are identified in this article.

Symptoms

A mounted Linux volume goes into read-only mode due to an MDM failure.

Cause

If only one MDM is available and no tie-breaker is available, ScaleIO places the volume into read-only mode. At this point, Linux makes the volume read-only as well.

Resolution

Ensure that there are at least two MDM nodes (a Primary and a tie-breaker).

Alternatively, you can place the MDM cluster in single node mode, but this is not recommended for a production environment.

Once this is done, you must reboot the Linux server to make the volume accessible again. If using VMware ESXi, perform a rescan of the storage devices. 

Affected Products

VxFlex Product Family

Products

VxFlex Product Family
Article Properties
Article Number: 000035966
Article Type: Solution
Last Modified: 05 Jan 2026
Version:  6
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