A página man de iostat diz:
The interval parameter specifies the amount of time in seconds between each
report. The first report contains statistics for the time since system
startup (boot), unless the -y option is used (in this case, this report is
omitted). Each subsequent report contains statistics collected during the
interval since the previous report.
Isso significa que a primeira saída de iostat -dx 1 será igual a iostat -dx , mas as saídas subsequentes são diferentes. - Você não pode reproduzir esse comportamento usando watch .