PG Num in Ceph Pool

[Deleted member 55360]

Hi everyone,

I am setting up a new ceph pool and i'm very stuck on the Pg_Num parameter.
I have 27 osd created with bluestore activated and journals placed on a dedicated ssd (for all HDD - partition=1G per OSD).

When i calculate the pg_num on https://ceph.com/pgcalc/ i obtain : 512 with the following parameters (see attachement).

Do you think that's good?

Thank you in advance.

 

[Alwin]

For the calculation you use 100% of %Data. This is used for the distribution of multiple pools.

 

[Deleted member 55360]

Ok thank you Alwin.
In fact, i have 27 OSD and i'm planning to create one pool for all my production.
After Ceph.com, they recommend to set pg_num to 1024 (between 10 and 50 OSDs).
Can you confirm this please?
What do you recommend if not?
Thank you

 

[Alwin]

You can always increase the PG number on a pool, but never decrease it. Take the value from the calculation.

 

[Deleted member 55360]

Ok thank you very much.