What is await iostat?
What’s meaning of await in iostat? $ man iostat await The average time (in milliseconds) for I/O requests issued to the device to be served. This includes the time spent by the requests in queue and the time spent servicing them. It is a measure of disk I/O latency in milliseconds.
What is %Util in iostat?
When iostat says %util, it means “Percentage of CPU time during which I/O requests were issued to the device”. The percentage of the time the drive was doing at least one thing. The iostat man page does provide a warning: Device saturation occurs when this value is close to 100% for devices serving requests serially.
What is Avgrq SZ?
avgrq-sz. The average size (in sectors) of the requests that were issued to the device. avgqu-sz. The average queue length of the requests that were issued to the device.
What’s the difference between Linux iostat and svctm?
1 Answer 1. On linux iostat, the await column (average wait) is showing the average time spent by an I/O request computed from its very beginning toward its end. The svctm column (service time) should display the average time spent servicing the request, i.e. the time spent “outside” the OS.
What is the await column in Linux iostat?
1 Answer 1. On linux iostat, the await column (average wait) is showing the average time spent by an I/O request computed from its very beginning toward its end.
Why is the await metric important in iostat?
A certain amount of queueing is generally unavoidable as modern storage devices reorder disk operations so as to improve overall performance. The await metric is the average time from when a request is put in the queue to when the request is completed.
What’s the difference between svctm and service time?
This includes the time spent by the requests in queue and the time spent servicing them. svctm The average service time (in milliseconds) for I/O requests that were issued to the device. Warning! Do not trust this field any more.