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

SQL Server According to Bob

JANUARY 11, 2020

The caching of data pages and grouping of log records helps remove much, if not all, of the command latency associated with a write operation. Action Description Manual Checkpoint – Target Specified I/O latency target set to ​​ the default ​​ of ​​ 20ms.

Servers 40

Servers Cache Database Media 40