Re: IO latency due to disk scrub

Pap,
 You did not mention the version of the Exadata software that is running on the mentioned X3. What version are you running ?

There was - to my understanding - an old Bug - that documented the disk scrub impacting user workloads...which should be fixed by now...The scrubbing is designed to only run when average I/O utilization is under 25%

Parameters controlling the disk scrubbing:

hardDiskScrubInterval - sets the interval for proactive resilvering of latent bad sectors. Valid options are daily, weekly, biweekly and none. Using the none option stops all disk scrubbing. hardDiskScrubStartTime command sets the start time for proactive resilvering of latent bad sectors. Valid options are a date/time combination or now.

Thanks,

--Rajesh

On Tue, Apr 27, 2021 at 12:15 AM Pap <oracle.developer35_at_gmail.com> wrote:

> Hi Listers, We are using the Exadata X3 machine and its Full Rack i.e. 14
> storage cell servers. We are seeing high disk IO utilization while the disk
> scrubbing was in progress. It is impacting the application jobs. This
> process made the disk IO utilization spiked from ~20% in BAU time to
> ~80-85% during the time disk scrubbing is in progress. And this process
> runs once every two week, which I believe is the default schedule.
>
> My question was , if it's okay to reschedule this
> process(harddiskscrubinterval) and make it monthly once? Does it have any
> negative impact? And if any other possible solution to make it not degrade
> the disk IO to so much extent?
>
> Regards
> Pap
>

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