What is the relationship of await, r_await and w_await in iostat -x command?
I want to know the relationship of the await, r_await and w_await
columns in the output from iostat -x.
Below is an example output of an iostat I/O statistics.
avg-cpu: %user %nice %system %iowait %steal %idle
7.55 0.01 5.70 7.31 0.00 79.44
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util
sdq 0.35 14.58 60.61 112.75 789.04 1172.86 22.63 1.45 8.39 17.76 3.35 1.19 20.65
sda 0.01 0.66 65.84 20.44 9450.37 2838.27 284.86 0.04 0.49 18.31 25.28 4.68 40.39
linux disk-utility
edited Jan 30 at 5:39
Scott
16.1k113990
asked Jan 30 at 1:41
user991704user991704
161
add a comment |
I want to know the relationship of the await, r_await and w_await
columns in the output from iostat -x.
Below is an example output of an iostat I/O statistics.
avg-cpu: %user %nice %system %iowait %steal %idle
7.55 0.01 5.70 7.31 0.00 79.44
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util
sdq 0.35 14.58 60.61 112.75 789.04 1172.86 22.63 1.45 8.39 17.76 3.35 1.19 20.65
sda 0.01 0.66 65.84 20.44 9450.37 2838.27 284.86 0.04 0.49 18.31 25.28 4.68 40.39
linux disk-utility
edited Jan 30 at 5:39
Scott
16.1k113990
asked Jan 30 at 1:41
user991704user991704
161
add a comment |
I want to know the relationship of the await, r_await and w_await
columns in the output from iostat -x.
Below is an example output of an iostat I/O statistics.
avg-cpu: %user %nice %system %iowait %steal %idle
7.55 0.01 5.70 7.31 0.00 79.44
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util
sdq 0.35 14.58 60.61 112.75 789.04 1172.86 22.63 1.45 8.39 17.76 3.35 1.19 20.65
sda 0.01 0.66 65.84 20.44 9450.37 2838.27 284.86 0.04 0.49 18.31 25.28 4.68 40.39
linux disk-utility
edited Jan 30 at 5:39
Scott
16.1k113990
asked Jan 30 at 1:41
user991704user991704
161
I want to know the relationship of the await, r_await and w_await
columns in the output from iostat -x.
Below is an example output of an iostat I/O statistics.
avg-cpu: %user %nice %system %iowait %steal %idle
7.55 0.01 5.70 7.31 0.00 79.44
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util
sdq 0.35 14.58 60.61 112.75 789.04 1172.86 22.63 1.45 8.39 17.76 3.35 1.19 20.65
sda 0.01 0.66 65.84 20.44 9450.37 2838.27 284.86 0.04 0.49 18.31 25.28 4.68 40.39
linux disk-utility
linux disk-utility
edited Jan 30 at 5:39
Scott
16.1k113990
asked Jan 30 at 1:41
user991704user991704
161
edited Jan 30 at 5:39
Scott
16.1k113990
asked Jan 30 at 1:41
user991704user991704
161
edited Jan 30 at 5:39
Scott
16.1k113990
edited Jan 30 at 5:39
Scott
16.1k113990
edited Jan 30 at 5:39
Scott
16.1k113990
16.1k113990
asked Jan 30 at 1:41
user991704user991704
161
asked Jan 30 at 1:41
user991704user991704
161
asked Jan 30 at 1:41
user991704user991704
161
161
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
await is 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.
r_await is 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 is 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.
You can go through the iostat manual for more information regarding the other outputs.
answered Jan 30 at 2:30
angelofdevangelofdev
929120
A casual reading of this answer (which is quoted directly from the man page) suggests that await should tend to be the average of r_await and w_await. This is (approximately) true for the first line in the example in the question (the line forsdq), but is not even close to being true for the second line (sda). Can you explain this?
– Scott
Jan 30 at 5:41
2
@Scott No I cannot answer this because it's the OP's example output. I would say that await refers to the request for the read/write to the device once the device receives this read/write request, is when the r_await and w_await kicks in. So it takes 0.04ms for the read/write request to be actioned by the device then 18.31ms on average for a read request to get actioned and compeleted and 25.28ms for a write request.
– angelofdev
Jan 30 at 5:49
add a comment |
Your Answer
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "3"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fsuperuser.com%2fquestions%2f1399903%2fwhat-is-the-relationship-of-await-r-await-and-w-await-in-iostat-x-command%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
await is 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.
r_await is 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 is 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.
You can go through the iostat manual for more information regarding the other outputs.
answered Jan 30 at 2:30
angelofdevangelofdev
929120
A casual reading of this answer (which is quoted directly from the man page) suggests that await should tend to be the average of r_await and w_await. This is (approximately) true for the first line in the example in the question (the line forsdq), but is not even close to being true for the second line (sda). Can you explain this?
– Scott
Jan 30 at 5:41
2
@Scott No I cannot answer this because it's the OP's example output. I would say that await refers to the request for the read/write to the device once the device receives this read/write request, is when the r_await and w_await kicks in. So it takes 0.04ms for the read/write request to be actioned by the device then 18.31ms on average for a read request to get actioned and compeleted and 25.28ms for a write request.
– angelofdev
Jan 30 at 5:49
add a comment |
await is 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.
r_await is 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 is 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.
You can go through the iostat manual for more information regarding the other outputs.
answered Jan 30 at 2:30
angelofdevangelofdev
929120
A casual reading of this answer (which is quoted directly from the man page) suggests that await should tend to be the average of r_await and w_await. This is (approximately) true for the first line in the example in the question (the line forsdq), but is not even close to being true for the second line (sda). Can you explain this?
– Scott
Jan 30 at 5:41
2
@Scott No I cannot answer this because it's the OP's example output. I would say that await refers to the request for the read/write to the device once the device receives this read/write request, is when the r_await and w_await kicks in. So it takes 0.04ms for the read/write request to be actioned by the device then 18.31ms on average for a read request to get actioned and compeleted and 25.28ms for a write request.
– angelofdev
Jan 30 at 5:49
add a comment |
await is 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.
r_await is 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 is 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.
You can go through the iostat manual for more information regarding the other outputs.
answered Jan 30 at 2:30
angelofdevangelofdev
929120
await is 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.
r_await is 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 is 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.
You can go through the iostat manual for more information regarding the other outputs.
answered Jan 30 at 2:30
angelofdevangelofdev
929120
edited Jan 30 at 2:49
answered Jan 30 at 2:30
angelofdevangelofdev
929120
answered Jan 30 at 2:30
angelofdevangelofdev
929120
answered Jan 30 at 2:30
angelofdevangelofdev
929120
929120
A casual reading of this answer (which is quoted directly from the man page) suggests that await should tend to be the average of r_await and w_await. This is (approximately) true for the first line in the example in the question (the line forsdq), but is not even close to being true for the second line (sda). Can you explain this?
– Scott
Jan 30 at 5:41
2
@Scott No I cannot answer this because it's the OP's example output. I would say that await refers to the request for the read/write to the device once the device receives this read/write request, is when the r_await and w_await kicks in. So it takes 0.04ms for the read/write request to be actioned by the device then 18.31ms on average for a read request to get actioned and compeleted and 25.28ms for a write request.
– angelofdev
Jan 30 at 5:49
add a comment |
A casual reading of this answer (which is quoted directly from the man page) suggests that await should tend to be the average of r_await and w_await. This is (approximately) true for the first line in the example in the question (the line forsdq), but is not even close to being true for the second line (sda). Can you explain this?
– Scott
Jan 30 at 5:41
2
@Scott No I cannot answer this because it's the OP's example output. I would say that await refers to the request for the read/write to the device once the device receives this read/write request, is when the r_await and w_await kicks in. So it takes 0.04ms for the read/write request to be actioned by the device then 18.31ms on average for a read request to get actioned and compeleted and 25.28ms for a write request.
– angelofdev
Jan 30 at 5:49
A casual reading of this answer (which is quoted directly from the man page) suggests that await should tend to be the average of r_await and w_await. This is (approximately) true for the first line in the example in the question (the line for
sdq), but is not even close to being true for the second line (sda). Can you explain this?– Scott
Jan 30 at 5:41
A casual reading of this answer (which is quoted directly from the man page) suggests that await should tend to be the average of r_await and w_await. This is (approximately) true for the first line in the example in the question (the line for
sdq), but is not even close to being true for the second line (sda). Can you explain this?– Scott
Jan 30 at 5:41
2
2
@Scott No I cannot answer this because it's the OP's example output. I would say that await refers to the request for the read/write to the device once the device receives this read/write request, is when the r_await and w_await kicks in. So it takes 0.04ms for the read/write request to be actioned by the device then 18.31ms on average for a read request to get actioned and compeleted and 25.28ms for a write request.
– angelofdev
Jan 30 at 5:49
@Scott No I cannot answer this because it's the OP's example output. I would say that await refers to the request for the read/write to the device once the device receives this read/write request, is when the r_await and w_await kicks in. So it takes 0.04ms for the read/write request to be actioned by the device then 18.31ms on average for a read request to get actioned and compeleted and 25.28ms for a write request.
– angelofdev
Jan 30 at 5:49
add a comment |
Thanks for contributing an answer to Super User!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fsuperuser.com%2fquestions%2f1399903%2fwhat-is-the-relationship-of-await-r-await-and-w-await-in-iostat-x-command%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
