PowerFlex VMware ATS Miscompare Errors When Deploying Multiple VMs

Summary: Virtual machine (VM) deployment from a Content Library (CL) takes a long time. ATS miscompare errors are seen in the vmkernel.log.

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Instructions

Scenario

This situation may occur while deploying multiple VMs on a single datastore simultaneously, or running any other vSphere operation which requires extensive locking on a virtual machines file system (VMFS) datastore.

For example:

  • Creating, growing, or locking a virtual machine file
  • Changing attributes of a file
  • Powering a virtual machine on or off
  • Creating or deleting a VMFS datastore
  • Expanding a VMFS datastore
  • Creating a template
  • Deploying a virtual machine from a template
  • Migrating a virtual machine with vMotion
  • And so on


Symptoms

vmkernel.log shows a high number of similar errors against a datastore:

2021-09-10T09:59:39.080Z cpu27:2098773)NMP: nmp_ThrottleLogForDevice:3872: Cmd 0x89 (0x459b0a7d8500, 3268605) to dev "eui.768dd94c75fbb70f058911e70000001f" on path "vmhba64:C0:T0:L31" Failed: H:0x0 D:0x2 P:0x0 Valid sense data: 0xe 0x1d 0x0. Act:NONE
2021-09-10T09:59:39.080Z cpu27:2098773)ScsiDeviceIO: 3483: Cmd(0x459b0a7d8500) 0x89, CmdSN 0x1c73c4e from world 3268605 to dev "eui.768dd94c75fbb70f058911e70000001f" failed H:0x0 D:0x2 P:0x0 Valid sense data: 0xe 0x1d 0x0.


Impact

Planned operations may work slower than expected. 


Root Cause

This is working as designed. Certain VMFS operations (VM creating, powering on, and so on) require putting a lock on a datastore in order to update the VMFS metadata. When such operations are happening simultaneously, they must compete for the datastore access which may delay them. If ATS-locking is enabled, only a part of a datastore is locked (unlike if a legacy SCSI reservation mechanism is used), but the result is the same, the same types of operations try to get a lock of the same metadata and compete for access.


Workaround

There is no workaround, this is working as designed.


Impacted Versions

This is not a PowerFlex issue.

Affected Products

PowerFlex Software
Article Properties
Article Number: 000194554
Article Type: How To
Last Modified: 30 Oct 2024
Version:  3
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