Re: Disk satuaration

Posted by ErmanArslansOracleBlog on Sep 06, 2021; 5:47pm
URL: http://erman-arslan-s-oracle-forum.124.s1.nabble.com/Disk-satuaration-tp10230p10231.html

It is about how busy the disk device is.
For a diskgroup (such a raid arrays, volume group etc), it is not quite a very useful indicator, because it's  basically showing how saturated "a" disk device is. So when you have multiple disk in the backend, it is just a percentage about how busy are those disks for serving at least one request. But those types of arrays or groups (i.e SSD or a RAID arrays) can do multiple I/Os at the same time.. So for RAID arrays and modern SSDs, this number does not reflect the performance limits. If you have a single device in the backend, then you can use this indicatior.. Higher percentage (for instance %100) -> higher saturation.

formal definition: Percentage of CPU time during which I/O requests were issued to the device