Comparing Ceph, Linstor, Mayastor and Vitastor Storage Performance in Kubernetes

Re:Comparing Ceph, Linstor, Mayastor and Vitastor Storage Pe... by IcePic on Wednesday June 08, 2022 @06:21AM (#31665330)

It still doesn't mean it accepts the write as finished when only 1 PG has it. I agree on the risks on why 2/1 is stupid, just not that this also means writes finish faster with min_size < replication_factor.

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Re:Comparing Ceph, Linstor, Mayastor and Vitastor Storage Pe... by tlamponi on Friday June 17, 2022 @01:18AM (#31774371)

It does though, it defines when to complete the write command to a client and when general any IO should be allowed on an object (both need #copies >= min-size), from the Quincy PG settings docs:

  > Sets the minimum number of written replicas for objects in the pool in order
  > to acknowledge an I/O operation to the client. If minimum is not met, Ceph
  > will not acknowledge the I/O to the client, which may result in data loss.
  > This setting ensures a minimum number of replicas when operating in degraded
  > mode.

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