Does `fstrim` causes write to all free blocks every time?Wireless connection connecting and disconnecting all...
Prisoner on alien planet escapes by making up a story about ghost companions and wins the war
Umlaut character order when sorting
Warnings using NDSolve on wave PDE. "Using maximum number of grid points" , "Warning: scaled local spatial error estimate"
How could empty set be unique if it could be vacuously false
Do I have to explain the mechanical superiority of the player-character within the fiction of the game?
Why isn't it a compile-time error to return a nullptr as a std::string?
Why is "Congress shall have power to enforce this article by appropriate legislation" necessary?
Drawing a second weapon as part of an attack?
Mathematically modelling RC circuit with a linear input
What does it cost to buy a tavern?
What constitutes a syllable?
What does this Swiss black on yellow rectangular traffic sign with a symbol looking like a dart mean?
Designing a magic-compatible polearm
Why does independence imply zero correlation?
King or Queen-Which piece is which?
"What is the maximum that Player 1 can win?"
Second 100 amp breaker inside existing 200 amp residential panel for new detached garage
How long did the SR-71 take to get to cruising altitude?
Can I enter the UK for 24 hours from a Schengen area, holding an Indian passport?
Improve appearance of the table in Latex
What are the current battlegrounds for people’s “rights” in the UK?
What triggered jesuits' ban on infinitesimals in 1632?
Why is oilcloth made with linseed oil?
Can the pre-order traversal of two different trees be the same even though they are different?
Does `fstrim` causes write to all free blocks every time?
Wireless connection connecting and disconnecting all the timeOpenVPN dropping connection every time intervalWhat is the /dev/disk/by-uuid/ and why does it use all free space on the diskWhy does dig take much longer than DNS query time?Why does fstrim trim all of the free space on my mdraid mirror after a reboot?Can't write to file system even though there is free space as said by df -hWhy every time I open the ubuntu file manager, are the hidden files displayed?How does fstrim keep finding bytes to trim on a Xen PV dom0?Unmount all your partitions to release/free up SSDExt4 - Last write time
.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty{ margin-bottom:0;
}
I have Ubuntu 18.04 server with 500G SSD disk which has LVM and dm-crypt on it.
I recently noticed that the number of bytes written to disk (as reported by vmstat -d or iostat) is unrealistically high. After monitoring the system I/O I found that the giant spike in disk writes happens once a week when fstrim.service runs:
From the logs, it looks like every week when fstrim runs it reports that basically all free space was written to the disk, even though the system is almost at idle and has just under 10Gb written in a week at most.
Is this an expected behavior? I always thought that only new free blocks since last fstrim run should be discarded, but not the entire free space each time. This puts absurdly high wear on SSD (judging by media wearout value as reported by disk). Or is it somehow related to the presence of dm-crypt?
The disk does support TRIM:
hdparm -I /dev/sda | grep TRIM
* Data Set Management TRIM supported (limit 8 blocks)
* Deterministic read ZEROs after TRIM
And discard pass through is also enabled in dm-crypt:
dmsetup table
silverbox--vg-swap: 0 19529728 linear 253:0 917964800
silverbox--vg-root: 0 917962752 linear 253:0 2048
sda3_crypt: 0 937496576 crypt aes-xts-plain64 00...0 0 8:3 4096 1 allow_discards
ubuntu disk ssd
asked 2 hours ago
OlegOleg
101
New contributor
Oleg is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
I have Ubuntu 18.04 server with 500G SSD disk which has LVM and dm-crypt on it.
I recently noticed that the number of bytes written to disk (as reported by vmstat -d or iostat) is unrealistically high. After monitoring the system I/O I found that the giant spike in disk writes happens once a week when fstrim.service runs:
From the logs, it looks like every week when fstrim runs it reports that basically all free space was written to the disk, even though the system is almost at idle and has just under 10Gb written in a week at most.
Is this an expected behavior? I always thought that only new free blocks since last fstrim run should be discarded, but not the entire free space each time. This puts absurdly high wear on SSD (judging by media wearout value as reported by disk). Or is it somehow related to the presence of dm-crypt?
The disk does support TRIM:
hdparm -I /dev/sda | grep TRIM
* Data Set Management TRIM supported (limit 8 blocks)
* Deterministic read ZEROs after TRIM
And discard pass through is also enabled in dm-crypt:
dmsetup table
silverbox--vg-swap: 0 19529728 linear 253:0 917964800
silverbox--vg-root: 0 917962752 linear 253:0 2048
sda3_crypt: 0 937496576 crypt aes-xts-plain64 00...0 0 8:3 4096 1 allow_discards
ubuntu disk ssd
asked 2 hours ago
OlegOleg
101
New contributor
Oleg is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
I have Ubuntu 18.04 server with 500G SSD disk which has LVM and dm-crypt on it.
I recently noticed that the number of bytes written to disk (as reported by vmstat -d or iostat) is unrealistically high. After monitoring the system I/O I found that the giant spike in disk writes happens once a week when fstrim.service runs:
From the logs, it looks like every week when fstrim runs it reports that basically all free space was written to the disk, even though the system is almost at idle and has just under 10Gb written in a week at most.
Is this an expected behavior? I always thought that only new free blocks since last fstrim run should be discarded, but not the entire free space each time. This puts absurdly high wear on SSD (judging by media wearout value as reported by disk). Or is it somehow related to the presence of dm-crypt?
The disk does support TRIM:
hdparm -I /dev/sda | grep TRIM
* Data Set Management TRIM supported (limit 8 blocks)
* Deterministic read ZEROs after TRIM
And discard pass through is also enabled in dm-crypt:
dmsetup table
silverbox--vg-swap: 0 19529728 linear 253:0 917964800
silverbox--vg-root: 0 917962752 linear 253:0 2048
sda3_crypt: 0 937496576 crypt aes-xts-plain64 00...0 0 8:3 4096 1 allow_discards
ubuntu disk ssd
asked 2 hours ago
OlegOleg
101
New contributor
Oleg is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
I have Ubuntu 18.04 server with 500G SSD disk which has LVM and dm-crypt on it.
I recently noticed that the number of bytes written to disk (as reported by vmstat -d or iostat) is unrealistically high. After monitoring the system I/O I found that the giant spike in disk writes happens once a week when fstrim.service runs:
From the logs, it looks like every week when fstrim runs it reports that basically all free space was written to the disk, even though the system is almost at idle and has just under 10Gb written in a week at most.
Is this an expected behavior? I always thought that only new free blocks since last fstrim run should be discarded, but not the entire free space each time. This puts absurdly high wear on SSD (judging by media wearout value as reported by disk). Or is it somehow related to the presence of dm-crypt?
The disk does support TRIM:
hdparm -I /dev/sda | grep TRIM
* Data Set Management TRIM supported (limit 8 blocks)
* Deterministic read ZEROs after TRIM
And discard pass through is also enabled in dm-crypt:
dmsetup table
silverbox--vg-swap: 0 19529728 linear 253:0 917964800
silverbox--vg-root: 0 917962752 linear 253:0 2048
sda3_crypt: 0 937496576 crypt aes-xts-plain64 00...0 0 8:3 4096 1 allow_discards
ubuntu disk ssd
ubuntu disk ssd
asked 2 hours ago
OlegOleg
101
New contributor
Oleg is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 2 hours ago
OlegOleg
101
New contributor
Oleg is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 2 hours ago
OlegOleg
101
New contributor
Oleg is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 2 hours ago
OlegOleg
101
asked 2 hours ago
OlegOleg
101
101
New contributor
Oleg is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Oleg is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
add a comment |
0
active
oldest
votes
Your Answer
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "106"
};
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: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
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
});
}
});
Oleg is a new contributor. Be nice, and check out our Code of Conduct.
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%2funix.stackexchange.com%2fquestions%2f525530%2fdoes-fstrim-causes-write-to-all-free-blocks-every-time%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
0
active
oldest
votes
0
active
oldest
votes
active
oldest
votes
active
oldest
votes
Oleg is a new contributor. Be nice, and check out our Code of Conduct.
Oleg is a new contributor. Be nice, and check out our Code of Conduct.
Oleg is a new contributor. Be nice, and check out our Code of Conduct.
Oleg is a new contributor. Be nice, and check out our Code of Conduct.
Thanks for contributing an answer to Unix & Linux Stack Exchange!
- 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%2funix.stackexchange.com%2fquestions%2f525530%2fdoes-fstrim-causes-write-to-all-free-blocks-every-time%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
