CPU Usage Incorrect in sys.dm_os_ring_buffers

Question

I'm running a cloud VPS with a SQL Server instance. Because it's for personal use, I'm using express edition (I can't use developer edition because I technically have production apps running on it and there's no way I could afford Standard+).

I'm trying to get baseline captures going using Brent Ozar's tutorial using sp_BlitzFirst. The problem I'm running into is that ProcessUtilization in sys.dm_os_ring_buffers always comes out as 100, no matter what the actual CPU usage is at the time.

VM Info

@@version: Microsoft SQL Server 2017 (RTM-CU15) (KB4498951) - 14.0.3162.1 (X64) May 15 2019 19:14:30 Copyright (C) 2017 Microsoft Corporation Express Edition (64-bit) on Linux (Ubuntu 18.04.2 LTS)

Host: 1 & 1 Ionos VPS

lscpu output

Architecture:        x86_64
CPU op-mode(s):      32-bit, 64-bit
Byte Order:          Little Endian
CPU(s):              2
On-line CPU(s) list: 0,1
Thread(s) per core:  1
Core(s) per socket:  1
Socket(s):           2
NUMA node(s):        1
Vendor ID:           GenuineIntel
CPU family:          6
Model:               63
Model name:          Intel(R) Xeon(R) Gold 5120 CPU @ 2.20GHz
Stepping:            0
CPU MHz:             2194.844
BogoMIPS:            4389.68
Hypervisor vendor:   VMware
Virtualization type: full
L1d cache:           32K
L1i cache:           32K
L2 cache:            1024K
L3 cache:            19712K
NUMA node0 CPU(s):   0,1
Flags:               fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts nopl xtopology tsc_reliable nonstop_tsc cpuid pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm cpuid_fault invpcid_single pti ssbd ibrs ibpb stibp fsgsbase tsc_adjust bmi1 avx2 smep bmi2 invpcid xsaveopt arat flush_l1d arch_capabilities

Answer 1

Microsoft says that DMV (ring buffers) doesn't work on SQL Server 2017, only 2019:

Sys.dm_os_ring_buffers DMV has been a key DMV used for monitoring SQL Server by built-in tools as well as third party monitoring utilities. When SQL Server 2017 was released on Linux, unfortunately this DMV did not return correct CPU usage information by SQL Server process. SQL Server team is glad to announce that the starting with SQL Server 2019 release candidate, the sys.dm_os_ring_buffers DMV returns SQL CPU utilization correctly.