Error 'CDB: Unmap/Read sub-channel TIMEOUT_ERROR' on Nutanix Virtual Machines

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Environment

SUSE Linux Enterprise Server 12 Service Pack 2 (SLES 12 SP2)
SUSE Linux Enterprise Server 12 Service Pack 3 (SLES 12 SP3)

Situation

This error is observed when performing fstrim of xfs file system LUN presented by Nutanix Acropolis hypervisor (AHV):

CDB: Unmap/Read sub-channel TIMEOUT_ERROR

Resolution

Fixed in:-

SUSE Linux Enterprise Server Service Pack 2: kernel-default-4.4.103-92.53.1
SUSE Linux Enterprise Server Service Pack 3: kernel-default-4.4.92-6.18.1

Cause

Unaligned SCSI unmap requests from fstrim cause disk congestion, I/O aborts and in extreme cases virtual machine hangs.

Additional Information

Disclaimer

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