Imagine we have a 3 OSDs cluster and I make an erasure pool with k=2 m=1. If I have an OSD fail, we can rebuild the data but (I think) the hole cluster won't be able to perform IOS.
Wouldn't be possible to make the cluster work in a degraded mode? I think it would be a good idea to make the cluster work on degraded mode and promise to re balance/re build whenever a third OSD comes alive. On reads, it could serve the data using the live data chunks and rebuilding (if necessary) the missing ones(using cpu to calculate the data before serving// with 0 RTA) or trying to rebuild the missing parts so it actually has the 2 data chunks on the 2 live OSDs (with some RTA and space usage) or even doing both things at the same time (with high network and cpu and storage cost). On writes, it could write the 2 data parts into the live OSDs and whenever the third OSD comes up, the cluster could re balance rebuilding the parity chunk and re positioning the parts so all OSDs have the same amount of data/work. would this be possible? ------------------------------------------------------------------------ *Jorge Pinilla López* jorp...@unizar.es Estudiante de ingenieria informática Becario del area de sistemas (SICUZ) Universidad de Zaragoza PGP-KeyID: A34331932EBC715A <http://pgp.rediris.es:11371/pks/lookup?op=get&search=0xA34331932EBC715A> ------------------------------------------------------------------------
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