On 10/27/2014 05:32 PM, Dan van der Ster wrote: > Hi, > > October 27 2014 5:07 PM, "Wido den Hollander" <wido@xxxxxxxx> wrote: >> On 10/27/2014 04:30 PM, Mike wrote: >> >>> Hello, >>> My company is plaining to build a big Ceph cluster for achieving and >>> storing data. >>> By requirements from customer - 70% of capacity is SATA, 30% SSD. >>> First day data is storing in SSD storage, on next day moving SATA storage. >> >> How are you planning on moving this data? Do you expect Ceph to do this? >> >> What kind of access to Ceph are you planning on using? RBD? Raw RADOS? >> The RADOS Gateway (S3/Swift)? >> >>> By now we decide use a SuperMicro's SKU with 72 bays for HDD = 22 SSD + >>> 50 SATA drives. >> >> That are some serious machines. It will require a LOT of CPU power in >> those machines to run 72 OSDs. Probably 4 CPUs per machine. >> >>> Our racks can hold 10 this servers and 50 this racks in ceph cluster = >>> 36000 OSD's, >> >> 36.000 OSDs shouldn't really be the problem, but you are thinking really >> big scale here. >> > > AFAIK, the OSDs should scale, since they only peer with ~100 others regardless of the cluster size. I wonder about the mon's though -- 36,000 OSDs will send a lot of pg_stats updates so the mon's will have some work to keep up. But the main issue I foresee is on the clients: don't be surprised when you see that each client needs close to 100k threads when connected to this cluster. A hypervisor with 10 VMs running would approach 1 million threads -- I have no idea if that will present any problems. There were discussions about limiting the number of client threads, but I don't know if there was any progress on that yet. > True about the mons. 3 monitors will not cut it here. You need 9 MONs at least I think, on dedicated resources. > Anyway, it would be good to know if there are any current installations even close to this size (even in test). We are in the early days of planning a 10k OSD test, but haven't exceed ~1200 yet. > > Cheers, Dan > > >>> With 4tb SATA drives and replica = 2 and nerfull ratio = 0.8 we have 40 >>> Petabyte of useful capacity. >>> >>> It's too big or normal use case for ceph? >> >> No, it's not to big for Ceph. This is what it was designed for. But a >> setup like this shouldn't be taken lightly. >> >> Think about the network connectivity required to connect all these >> machines and other decisions to be made. >> >> _______________________________________________ >>> ceph-users mailing list >>> ceph-users@xxxxxxxxxxxxxx >>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >> >> -- >> Wido den Hollander >> 42on B.V. >> Ceph trainer and consultant >> >> Phone: +31 (0)20 700 9902 >> Skype: contact42on >> _______________________________________________ >> ceph-users mailing list >> ceph-users@xxxxxxxxxxxxxx >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com -- Wido den Hollander 42on B.V. Ceph trainer and consultant Phone: +31 (0)20 700 9902 Skype: contact42on _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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