Re: Innodb unexplained IOs

[Jeff Cobb]

I work with Bob and can provide a few more details. We are seeing this I/O activity continue.

To recap, we see (for days on end) 4-5MBps reads from the storage volume that holds
our innodb spaces. With mysql down, there are no reads. As soon as we bring mysql
up, with no queries running (as seen via mytop or mysqladmin proc), the reads begin.
Every 30 seconds or so, there is a ~ 600KB write - no other writes.

At this rate of reading, our entire database could be read several times per day.

We did have a job that was deleting large bits of our largest tables. We turned this job
off 3 days ago and the mystery I/O continues.

We saw today that this activity apparently stops during a table check (any table), only to
start back up once the table check completes.

Any further ideas would be greatly appreciated!