(sorry for empty mail just before)

> i'm plannung to split the block db to a seperate flash device which i
>> also would like to use as an OSD for erasure coding metadata for rbd
>> devices.
>>
>> If i want to use 14x 14TB HDDs per Node
>>
>> https://docs.ceph.com/docs/master/rados/configuration/bluestore-config-ref/#sizing
>>
>> recommends a minimum size of 140GB per 14TB HDD.
>>
>> Is there any recommandation of how many osds a single flash device can
>> serve? The optane ones can do 2000MB/s write + 500.000 iop/s.
>>
>
>
I think many ceph admins are more concerned with having many drives
co-using the same DB drive, since if the DB drive fails, it also means all
OSDs are lost at the same time.
Optanes and decent NVMEs are probably capable of handling tons of HDDs, so
that the bottleneck ends up being somewhere else, but the failure scenarios
are a bit scary if the whole host is lost just by that one DB device acting
up.

-- 
May the most significant bit of your life be positive.
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