Whether read I/O is accpted when the number of replica is under pool's min_size
Hi, Could you tell me whether read I/O is acxepted when the number of replicas is under pool's min_size? I read the official document and found that there is a difference of the effect of pool's min_size between pool's document and the pool's configuration document. Pool's document: https://docs.ceph.com/en/latest/rados/operations/pools/
To set a minimum number of required replicas for I/O, you should use the min_size setting.
Pool's configuration document. https://docs.ceph.com/en/latest/rados/configuration/pool-pg-config-ref/
osd pool default min size Description
Sets the minimum number of written replicas for objects in the pool in order to acknowledge a write operation to the client. The former says that min_size is related to both read/write I/O. On the other hands, the latter says it's only about write I/O. So which is correct description? As a result of my verification, the former looks correct. I created a RGW object in a pool having 3 replicas and its min_size is 2. Both read and write aren't accepted when 2 replicas are gone. Thanks, Satoru
Hi, it's correct that both read and write I/O is paused when a pool's min_size is not met. Regards, Eugen Zitat von Satoru Takeuchi <satoru.takeuchi@gmail.com>:
Hi,
Could you tell me whether read I/O is acxepted when the number of replicas is under pool's min_size?
I read the official document and found that there is a difference of the effect of pool's min_size between pool's document and the pool's configuration document.
Pool's document: https://docs.ceph.com/en/latest/rados/operations/pools/
To set a minimum number of required replicas for I/O, you should use the min_size setting.
Pool's configuration document. https://docs.ceph.com/en/latest/rados/configuration/pool-pg-config-ref/
osd pool default min size Description
Sets the minimum number of written replicas for objects in the pool in order to acknowledge a write operation to the client.
The former says that min_size is related to both read/write I/O.
On the other hands, the latter says it's only about write I/O. So which is correct description?
As a result of my verification, the former looks correct.
I created a RGW object in a pool having 3 replicas and its min_size is 2.
Both read and write aren't accepted when 2 replicas are gone.
Thanks,
Satoru _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io
2020年12月15日(火) 18:48 Eugen Block <eblock@nde.ag>:
Hi,
it's correct that both read and write I/O is paused when a pool's min_size is not met.
Regards, Eugen
Thank you! I'll send a PR to fix the Pool's configuration document. Regards, Satoru Satoru
Zitat von Satoru Takeuchi <satoru.takeuchi@gmail.com>:
Hi,
Could you tell me whether read I/O is acxepted when the number of replicas is under pool's min_size?
I read the official document and found that there is a difference of the effect of pool's min_size between pool's document and the pool's configuration document.
Pool's document: https://docs.ceph.com/en/latest/rados/operations/pools/
To set a minimum number of required replicas for I/O, you should use the min_size setting.
Pool's configuration document. https://docs.ceph.com/en/latest/rados/configuration/pool-pg-config-ref/
osd pool default min size Description
Sets the minimum number of written replicas for objects in the pool in order to acknowledge a write operation to the client.
The former says that min_size is related to both read/write I/O.
On the other hands, the latter says it's only about write I/O. So which is correct description?
As a result of my verification, the former looks correct.
I created a RGW object in a pool having 3 replicas and its min_size is 2.
Both read and write aren't accepted when 2 replicas are gone.
Thanks,
Satoru _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io
_______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io
participants (2)
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Eugen Block
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Satoru Takeuchi