VMware ESXi: esxcli command fail with "error: device naa.<wwn> unknown"

Summary: VMware ESXi: esxcli command fail with "error: device naa. unknown"

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Symptoms

Received an error when trying to adjust the IOPS value to 1 instead of 1000(default) as per Dell best practices.

Error msg (for ESXi 5.x/6.x):

#esxcli storage nmp psp roundrobin deviceconfig get --device=naa.<wwn>
   Byte Limit: 10485760
   Device: naa.<wwn>
   IO Operation Limit: 1000
   Limit Type: Default
   Use Active Unoptimized Paths: false

#esxcli storage nmp psp roundrobin deviceconfig set --device=naa.<wwn>  --iops=1 --type iops
error: device naa.<wwn> unknown.

 

Cause

N/A

 

Resolution

Workaround:
Try using the same command, but with different syntax:

#esxcli storage nmp psp roundrobin deviceconfig set  type=iops  iops 1  device naa.<wwn>

This performed correctly (with no output)
The device "naa.<wwn>" has now been set to round robin and IOPS=1 as recommend:

#esxcli storage nmp psp roundrobin deviceconfig get --device=naa.<wwn>
   Byte Limit: 10485760 <wwn>
   IO Operation Limit: 1
   Limit Type: Iops
   Use Active Unoptimized Paths: false

 

Affected Products

Symmetrix

Products

Symmetrix, Symmetrix DMX Series, VMAX
Article Properties
Article Number: 000052272
Article Type: Solution
Last Modified: 12 Nov 2025
Version:  4
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