Bcache writeback_percent max value
Clash Royale CLAN TAG#URR8PPP
up vote
1
down vote
favorite
I'm tryng to set
writeback_percent
at a value > 40 but it only accept value between 0 and 40.
If i set
echo 50 > /sys/block/bcache0/bcache/writeback_percent
then when i read the value
more /sys/block/bcache0/bcache/writeback_percent
i have 40.
For value<=40 the settings work fine.
My setting for cache type are
more /sys/block/bcache0/bcache/cache_mode
writethrough [writeback] writearound none
I know this is dangerous but this is not a problem for me.
As far as i understand writeback_percent is the % used from dirty data in cache, why i can't use 90% or 100% of available space?
May be i dont' understand quite well this settings?
bcache
asked Sep 10 '17 at 13:06
Antimo
61
add a comment |Â
up vote
1
down vote
favorite
I'm tryng to set
writeback_percent
at a value > 40 but it only accept value between 0 and 40.
If i set
echo 50 > /sys/block/bcache0/bcache/writeback_percent
then when i read the value
more /sys/block/bcache0/bcache/writeback_percent
i have 40.
For value<=40 the settings work fine.
My setting for cache type are
more /sys/block/bcache0/bcache/cache_mode
writethrough [writeback] writearound none
I know this is dangerous but this is not a problem for me.
As far as i understand writeback_percent is the % used from dirty data in cache, why i can't use 90% or 100% of available space?
May be i dont' understand quite well this settings?
bcache
asked Sep 10 '17 at 13:06
Antimo
61
Thank you @sourcedj, but may be i'm wrong but previously i was able to use a value > 40. This are file systems in use only for automatic test purpose so data are copied from a source that is not cached , backupped and so on so no problem if i lost this data. Anyway i understand that probability of data loss increase but i can't find any info about this limit, so i ask here about some clarification. And anyway my English is not perfect :)
– Antimo
Sep 10 '17 at 19:36
Sorry, I was criticizing only a small detail. Don't worry about it. It sounds like I wasn't very helpful! I don't know why bcache is not accepting a value > 40. It's a perfectly reasonable question to have, hopefully someone who knows more will see your post.
– sourcejedi
Sep 10 '17 at 19:44
add a comment |Â
up vote
1
down vote
favorite
up vote
1
down vote
favorite
I'm tryng to set
writeback_percent
at a value > 40 but it only accept value between 0 and 40.
If i set
echo 50 > /sys/block/bcache0/bcache/writeback_percent
then when i read the value
more /sys/block/bcache0/bcache/writeback_percent
i have 40.
For value<=40 the settings work fine.
My setting for cache type are
more /sys/block/bcache0/bcache/cache_mode
writethrough [writeback] writearound none
I know this is dangerous but this is not a problem for me.
As far as i understand writeback_percent is the % used from dirty data in cache, why i can't use 90% or 100% of available space?
May be i dont' understand quite well this settings?
bcache
asked Sep 10 '17 at 13:06
Antimo
61
I'm tryng to set
writeback_percent
at a value > 40 but it only accept value between 0 and 40.
If i set
echo 50 > /sys/block/bcache0/bcache/writeback_percent
then when i read the value
more /sys/block/bcache0/bcache/writeback_percent
i have 40.
For value<=40 the settings work fine.
My setting for cache type are
more /sys/block/bcache0/bcache/cache_mode
writethrough [writeback] writearound none
I know this is dangerous but this is not a problem for me.
As far as i understand writeback_percent is the % used from dirty data in cache, why i can't use 90% or 100% of available space?
May be i dont' understand quite well this settings?
bcache
bcache
asked Sep 10 '17 at 13:06
Antimo
61
asked Sep 10 '17 at 13:06
Antimo
61
asked Sep 10 '17 at 13:06
Antimo
61
asked Sep 10 '17 at 13:06
Antimo
61
asked Sep 10 '17 at 13:06
Antimo
61
61
Thank you @sourcedj, but may be i'm wrong but previously i was able to use a value > 40. This are file systems in use only for automatic test purpose so data are copied from a source that is not cached , backupped and so on so no problem if i lost this data. Anyway i understand that probability of data loss increase but i can't find any info about this limit, so i ask here about some clarification. And anyway my English is not perfect :)
– Antimo
Sep 10 '17 at 19:36
Sorry, I was criticizing only a small detail. Don't worry about it. It sounds like I wasn't very helpful! I don't know why bcache is not accepting a value > 40. It's a perfectly reasonable question to have, hopefully someone who knows more will see your post.
– sourcejedi
Sep 10 '17 at 19:44
add a comment |Â
Thank you @sourcedj, but may be i'm wrong but previously i was able to use a value > 40. This are file systems in use only for automatic test purpose so data are copied from a source that is not cached , backupped and so on so no problem if i lost this data. Anyway i understand that probability of data loss increase but i can't find any info about this limit, so i ask here about some clarification. And anyway my English is not perfect :)
– Antimo
Sep 10 '17 at 19:36
Sorry, I was criticizing only a small detail. Don't worry about it. It sounds like I wasn't very helpful! I don't know why bcache is not accepting a value > 40. It's a perfectly reasonable question to have, hopefully someone who knows more will see your post.
– sourcejedi
Sep 10 '17 at 19:44
Thank you @sourcedj, but may be i'm wrong but previously i was able to use a value > 40. This are file systems in use only for automatic test purpose so data are copied from a source that is not cached , backupped and so on so no problem if i lost this data. Anyway i understand that probability of data loss increase but i can't find any info about this limit, so i ask here about some clarification. And anyway my English is not perfect :)
– Antimo
Sep 10 '17 at 19:36
Thank you @sourcedj, but may be i'm wrong but previously i was able to use a value > 40. This are file systems in use only for automatic test purpose so data are copied from a source that is not cached , backupped and so on so no problem if i lost this data. Anyway i understand that probability of data loss increase but i can't find any info about this limit, so i ask here about some clarification. And anyway my English is not perfect :)
– Antimo
Sep 10 '17 at 19:36
Sorry, I was criticizing only a small detail. Don't worry about it. It sounds like I wasn't very helpful! I don't know why bcache is not accepting a value > 40. It's a perfectly reasonable question to have, hopefully someone who knows more will see your post.
– sourcejedi
Sep 10 '17 at 19:44
Sorry, I was criticizing only a small detail. Don't worry about it. It sounds like I wasn't very helpful! I don't know why bcache is not accepting a value > 40. It's a perfectly reasonable question to have, hopefully someone who knows more will see your post.
– sourcejedi
Sep 10 '17 at 19:44
add a comment |Â
1 Answer
1
active
oldest
votes
up vote
0
down vote
This is hardcoded value in the bcache drive code - linux/drivers/md/bcache/writeback.h. The only way to change this limit is to rebuild the driver from source.
answered 9 mins ago
V.Gorbunov
1
New contributor
V.Gorbunov 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 |Â
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
0
down vote
This is hardcoded value in the bcache drive code - linux/drivers/md/bcache/writeback.h. The only way to change this limit is to rebuild the driver from source.
answered 9 mins ago
V.Gorbunov
1
New contributor
V.Gorbunov 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 |Â
up vote
0
down vote
This is hardcoded value in the bcache drive code - linux/drivers/md/bcache/writeback.h. The only way to change this limit is to rebuild the driver from source.
answered 9 mins ago
V.Gorbunov
1
New contributor
V.Gorbunov 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 |Â
up vote
0
down vote
up vote
0
down vote
This is hardcoded value in the bcache drive code - linux/drivers/md/bcache/writeback.h. The only way to change this limit is to rebuild the driver from source.
answered 9 mins ago
V.Gorbunov
1
New contributor
V.Gorbunov is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
This is hardcoded value in the bcache drive code - linux/drivers/md/bcache/writeback.h. The only way to change this limit is to rebuild the driver from source.
answered 9 mins ago
V.Gorbunov
1
New contributor
V.Gorbunov is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 9 mins ago
V.Gorbunov
1
New contributor
V.Gorbunov is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 9 mins ago
V.Gorbunov
1
answered 9 mins ago
V.Gorbunov
1
1
New contributor
V.Gorbunov is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
V.Gorbunov is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
V.Gorbunov 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 |Â
add a comment |Â
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
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2funix.stackexchange.com%2fquestions%2f391435%2fbcache-writeback-percent-max-value%23new-answer', 'question_page');
);
Post as a guest
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
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
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
Thank you @sourcedj, but may be i'm wrong but previously i was able to use a value > 40. This are file systems in use only for automatic test purpose so data are copied from a source that is not cached , backupped and so on so no problem if i lost this data. Anyway i understand that probability of data loss increase but i can't find any info about this limit, so i ask here about some clarification. And anyway my English is not perfect :)
– Antimo
Sep 10 '17 at 19:36
Sorry, I was criticizing only a small detail. Don't worry about it. It sounds like I wasn't very helpful! I don't know why bcache is not accepting a value > 40. It's a perfectly reasonable question to have, hopefully someone who knows more will see your post.
– sourcejedi
Sep 10 '17 at 19:44