sar, iostat shows excessive '%util' value for sr0/scd0 device

Issue

• sar, iostat shows excessive %util value for sr0/scd0 devices:

  $ sar -d -p -f /var/log/sa/sa21
  Linux 4.18.0-425.3.1.el8.x86_64 (testvm)     01/21/2023      _x86_64_        (4 CPU)
  12:10:21 AM       DEV       tps     rkB/s     wkB/s   areq-sz    aqu-sz     await     svctm     %util
  12:10:21 AM       sr0      0.00      0.00      0.00      0.00      0.00      0.00      0.00      0.00
  12:10:21 AM rhel-root      4.89     47.97     21.56     14.23      0.00      0.77      0.49      0.24
  12:10:21 AM rhel-swap      0.12      0.48      0.00      4.00      0.00      0.65      0.28      0.00
  12:10:21 AM       sda      3.09     26.46     21.40     15.51      0.00      0.82      0.47      0.15
  12:10:21 AM       sr0      0.00      0.00      0.00      0.00      0.00      0.00      0.00   7566.38   <---
  12:10:21 AM rhel-root      3.32     25.94     21.40     14.24      0.00      0.83      0.42      0.14
  12:10:21 AM rhel-swap      0.13      0.52      0.00      4.00      0.00      0.72      0.42      0.01
  12:10:21 AM       sda      4.33     23.99     22.62     10.75      0.00      0.64      0.38      0.16
  12:10:21 AM       sr0      0.00      0.00      0.00      0.00      0.00      0.00      0.00      0.00
  [...]
  

• iostat -t -x 10 output:

  $ less iostat.txt |grep "scd0"|sort -nrk 16,16|head
  Device            r/s     w/s     rkB/s     wkB/s   rrqm/s   wrqm/s  %rrqm  %wrqm r_await w_await aqu-sz rareq-sz wareq-sz  svctm  %util
  scd0             0.00    0.00      0.00      0.00     0.00     0.00   0.00   0.00    0.00    0.00   0.00     0.00     0.00   0.00 306094.18      <---
  
  scd0             0.00    0.00      0.00      0.00     0.00     0.00   0.00   0.00    0.00    0.00   0.00     0.00     0.00   0.00 146756.34      <---
  
  scd0             0.00    0.00      0.00      0.00     0.00     0.00   0.00   0.00    0.00    0.00   0.00     0.00     0.00   0.00 125112.17      <---
  
  scd0             0.00    0.00      0.00      0.00     0.00     0.00   0.00   0.00    0.00    0.00   0.00     0.00     0.00   0.00 55500.75      <---
  
  scd0             0.00    0.00      0.00      0.00     0.00     0.00   0.00   0.00    0.00    0.00   0.00     0.00     0.00   0.00 13218.73      <---
  [...]