bionmlm.blogg.se - Setup openzfs on freebsd

These statistics can reveal the health of specific disks. This view displays extended statistics for the entire system, including every disk device available on the system. However, if the system shows mostly kernel and interrupt use, there may be an i/o throughput limitation to investigate further.Įxtended device data is available with the ‘-x’ switch extended device statisticsĭevice r/s w/s kr/s kw/s ms/r ms/w ms/o ms/t qlen %b

A system with high user cpu utilization may not be i/o bound. These stats must be interpreted with an understanding of the workload. The CPU statistics can be used to verify that the system was under load, while also looking at the storage.

MB/s: total throughput in megabytes/sec (Both reads and writes)Ĭpu: percent of time spent split into the following:.

tps: transaction frequency (per second).

KB/t: average (mean) size of transaction in KB.

tin: typewriter bytes in (* see ‘-d’ flag in the reducing cognitive load).

This Column also vertically delineates the statistics for the device. With no other arguments, iostat produces the following output: tty nvd0 ada0 da0 cpu You can use it to determine usage patterns, bottlenecks and poor behavior at a glance. It can produce data to support conclusions and suggest further avenues of investigation when used judiciously. In this article, we will dissect its output and introduce disk subsystem troubleshooting using statistical output from iostat. Iostat provides a window into the i/o effort of the storage subsystem.