Hello,
Correct me if I'm wrong, but isn't your configuration just twice as bad as running with replication size=2? With replication size=2 when you lose a disk you lose data if there is even one defect block found when ceph is reconstructing the pgs that had a replica on the failed disk. No, with your setup you have to be able to read twice as much data correctly in order to reconstruct the pgs. When using EC I think that you have to use m>1 in production. -- Eino Tuominen ________________________________ From: ceph-users <[email protected]> on behalf of Jorge Pinilla López <[email protected]> Sent: Tuesday, October 24, 2017 11:24 To: [email protected] Subject: Re: [ceph-users] Erasure Pool OSD fail Okay I think I can respond myself, the pool is created with a default min_size of 3, so when one of the OSDs goes down, the pool doenst perform any IO, manually changing the the pool min_size to 2 worked great. El 24/10/2017 a las 10:13, Jorge Pinilla López escribió: I am testing erasure code pools and doing a rados test write to try fault tolerace. I have 3 Nodes with 1 OSD each, K=2 M=1. While performing the write (rados bench -p replicate 100 write), I stop one of the OSDs daemons (example osd.0), simulating a node fail, and then the hole write stops and I can't write any data anymore. 1 16 28 12 46.8121 48 1.01548 0.616034 2 16 40 24 47.3907 48 1.04219 0.923728 3 16 52 36 47.5889 48 0.593145 1.0038 4 16 68 52 51.6633 64 1.39638 1.08098 5 16 74 58 46.158 24 1.02699 1.10172 6 16 83 67 44.4711 36 3.01542 1.18012 7 16 95 79 44.9722 48 0.776493 1.24003 8 16 95 79 39.3681 0 - 1.24003 9 16 95 79 35.0061 0 - 1.24003 10 16 95 79 31.5144 0 - 1.24003 11 16 95 79 28.6561 0 - 1.24003 12 16 95 79 26.2732 0 - 1.24003 Its pretty clear where the OSD failed On the other hand, using a replicated pool, the client (rados test) doesnt even notice the OSD fail, which is awesome. Is this a normal behaviour on EC pools? ________________________________ Jorge Pinilla López [email protected]<mailto:[email protected]> 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> ________________________________ _______________________________________________ ceph-users mailing list [email protected]<mailto:[email protected]> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com -- ________________________________ Jorge Pinilla López [email protected]<mailto:[email protected]> 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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