Comments - Which disk does innodb_io_capacity impact?
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The parameters
innodb_io_capacity
andinnodb_io_capacity_max
are measured in data pages written per second. If the doublewrite buffer is enabled (it should, unless your storage supports atomic writes), then the number of pages per second should be half the number of bytes per second divided byinnodb_page_size
.The setting mostly controls the data page writes related to checkpoint flushing. The setting is global for all data files; there is no per-file setting.
The checkpoint flushing was recently rewritten in MDEV-23855.
"innodb_io_capacity and innodb_io_capacity_max control the InnoDB background tasks activity, including merging data from the insert buffer and flushing pages."
https://mariadb.com/kb/en/innodb-system-variables/#innodb_io_capacity
The innodb background task flushes dirty blocks from InnoDB buffer pool to disk. These dirty blocks can be blocks from tables or indexes or the double write buffer? Those are located either in ibdata? or in all *.ibd files. So it is relevant where those files are located...
So in your case I think it is the RAID array.
Thanks Oli, That's exactly what I was looking for.