>From ceph website: "Deep scrubbing (weekly) reads the data and uses checksums to ensure data integrity.” 1. Why do you use "weekly" deep scrubbing? How many times a year one disk is scrubbed on average in a Ceph cluster? Schwartz* used three times per year. “Interestingly, we did not observe a further decrease in data loss as we increased the scrubbing frequency from three to eleven times per year; rather, a slight increase in data loss was noticed. This phenomenon comes from the POH (power-on-hour) effect on drive reliability. Aggressive scrubbing requires more power cycles, adversely affecting drive reliability. " 2. Do you have different scrubbing policies according to the redundancy method? For example, more scrubs when using replication rather than erasure coding? *Schwarz, Thomas JE, et al. "Disk scrubbing in large archival storage systems." *Modeling, Analysis, and Simulation of Computer and Telecommunications Systems, 2004.(MASCOTS 2004). Proceedings. The IEEE Computer Society's 12th Annual International Symposium on*. IEEE, 2004. Thanks, -- Vero EG -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
