Brendan Gregg

MAY 8, 2021

It seemed to have several set speeds, and when pushing hard it would try a faster speed for a couple of seconds, then a faster one, until it found the fastest it could operate (presumably it tries faster speeds until it begins to get sector-ECC errors). Note the sdb latencies range from 32 ms to over 2 seconds!

Performance 142

Performance Latency Speed Systems 142

Brendan Gregg

MAY 8, 2021

It seemed to have several set speeds, and when pushing hard it would try a faster speed for a couple of seconds, then a faster one, until it found the fastest it could operate (presumably it tries faster speeds until it begins to get sector-ECC errors). I could hear it spin faster. Hit Ctrl-C to end. Hit Ctrl-C to end.

Performance 40

Performance Latency Speed Systems 40

Brendan Gregg

MAY 8, 2021

It seemed to have several set speeds, and when pushing hard it would try a faster speed for a couple of seconds, then a faster one, until it found the fastest it could operate (presumably it tries faster speeds until it begins to get sector-ECC errors). Note the sdb latencies range from 32 ms to over 2 seconds!

Performance 40

Performance Latency Speed Systems 40