rd_sec/s: Number of sectors read from the device. The size of a sector is 512
bytes.
wr_sec/s: Number of sectors written to the device. The size of a sector is
512 bytes.
%util: Percentage of CPU time during which I/O requests were issued to the
device (bandwidth utilization for the device). Device saturation occurs when
this value is close to 100%.
Minor: Objects are allocated in eden, and because of infant mortality most
objects die there. When Eden fills up it causes a minor collection, in which
some surviving objects are moved to an older generation
Major: (aka Full GC) When older generations need to be collected there is a major
collection that is often much slower because it involves all living objects.
Throughput 1min: This is the percentage of total time not spent in garbage collection,
considered over the last minute.