Disk Statistics (per second) ut% is the percent of time the disk was busy. xfers is the number of data-transfer commands issued per second. xfers = ureads + writes + cpreads + greads + gwrites chain is the average number of 4K blocks per command. usecs is the average disk round-trip time per 4K block.
ANY1+ reports near to 100%, even though individual cores report low. ANY1+ represents the amount of time that at least one CPU core was busy doing work in a second. This can very easily give a false report of actual CPU levels on a storage system- especially systems with a high number of cores. A Perfstat issubmitted and reviewed, and it shows that no other issues are present. ANY1+ reads 100% very easily, and this is where UM and many other tools get their CPU information from.