PowerStore: Active/active IOs to the same LBA on both nodes may lead to uncorrectable errors

Summary: Active/Active IOs to the same LBA on both nodes from VPLEX or hosts may lead to uncorrectable errors.

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Symptoms

When active/active IOs that are smaller than 4K access the same Logical Block Address (LBA) on both appliance nodes around the same time, an uncorrectable error may occur when an internal software buffer is reused before the nodes sync up because of a timing issue.

If the symptom is detected:
  • VPLEX may fail to read some LBA ranges and mark the LUN as dead, and detaching/attaching the affected LUN will not resolve the condition.
  • Hosts may return IO errors from the affected LUN.

Cause

Due to a PowerStore software issue, there is a corner case where if IOs are sent to both nodes simultaneously for the same LBA range or descendent LBAs through snapshots, a race condition may occur, and the page is marked as corrupted due to a checksum failure as one node updates the page while the other node is preparing to update the page. 

This symptom may occur when all of the following conditions are met: 
  • VPLEX code version below 6.2.0.05.00.11 is used with the PowerStore appliance, or Multipath software misconfigured (Active/Active instead of ALUA) on the hosts.
    • There is a known issue in the VPLEX code version below 6.2.0.05.00.11 that sends small IOs to both PowerStore Node A and Node B simultaneously for the same LUN.
  • Both writes must arrive near simultaneously on both nodes.
  • Both writes must be to the same page and LBA range.
  • The first arriving writes can be any size but are not yet flushed, while later arriving writes must be small, less than 4K.

Resolution

If the symptom is detected, escalate to Technical Support for further assistance immediately.

To prevent the issue from occurring:
If VPLEX is used, upgrade VPLEX to 6.2.0.05.00.11 (6.2 P5) or later, or to the latest target version which includes the related fix.
  • Verify Multipath software configurations from the host side, follow the Host Configuration Guide.
  • Upgrade PowerStoreOS to version 3.6.0 or later that includes the relevant fix.

This issue is fixed in PowerStoreOS 3.6.0 and above.

Affected Products

PowerStore
Article Properties
Article Number: 000218691
Article Type: Solution
Last Modified: 14 Jun 2025
Version:  3
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