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Erasure Coded Pool suggested PG count


I'm messing around with pg calculator to figure out the best pg count for my cluster. I have an erasure coded FS pool which will most likely use half space of the cluster in the forseeable future. But the pg calculator only has options for replicated pools. Should i just type according to the erasure-code ratio for replica # or is there another way around this?


Solution

  • From Ceph Nautilus version onwards there's a pg-autoscaler that does the scaling for you. You just need to create a pool with an initial (maybe low) value. As for the calculation itself your assumption is correct, you take the number of chunks into account when planning the pg count.