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Linuxコマンド iostat -x で出力される各項目とその意味(日本語意訳)

ドキュメントの英語の原文と、筆者による日本語の意訳

sebastien.godard.pagesperso-orange.fr

r/s
完了した読み取りリクエスト数/s
The number (after merges) of read requests completed per second for the device. 

w/s
完了した書き込みリクエスト数/s
The number (after merges) of write requests completed per second for the device.

rsec/s (rkB/s, rMB/s)
デバイスから読み込まれるセクタ数[KB/s]
The number of sectors (kilobytes, megabytes) read from the device per second. 

wsec/s (wkB/s, wMB/s)
デバイスに書き込まれるセクタ数[KB/s]
The number of sectors (kilobytes, megabytes) written to the device per second.

rrqm/s
キューに入ってマージされた読み取り要求数/s
The number of read requests merged per second that were queued to the device. 

wrqm/s
キューに入ってマージされた書き込み要求数/s
The number of write requests merged per second that were queued to the device.

%rrqm
デバイス送信前にマージされた読み取り要求率[%]
The percentage of read requests merged together before being sent to the device.

%wrqm
書き込み要求がデバイス送信前にマージされた率[%]
The percentage of write requests merged together before being sent to the device.

r_await
読み取り要求平均時間[ms]
The average time (in milliseconds) for read requests issued to the device to be served. This includes the time spent by the requests in queue and the time spent servicing them.

w_await
書き込み処理平均時間[ms]
The average time (in milliseconds) for write requests issued to the device to be served. This includes the time spent by the requests in queue and the time spent servicing them.

aqu-sz
リクエストの平均キュー長
The average queue length of the requests that were issued to the device.
Note: In previous versions, this field was known as avgqu-sz.

%util
デバイスの帯域幅の使用率 (RAIDやSSDの場合は意味合いが違うかも)
Percentage of elapsed 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% for devices serving requests serially. But for devices serving requests in parallel, such as RAID arrays and modern SSDs, this number does not reflect their performance limits.