Hi, I'm designing a new ceph pool with new hardware and I would like to receive some suggestion. I want to use a replica count of 3 in the pool and the idea is to buy 3 new servers with a 10-drive 2,5" chassis each and 2 10Gbps nics. I have in mind two configurations: 1- With journal in SSDs OS: 2xSSD intel SC3500 100G Raid 1 Journal: 2xSSD intel SC3700 100G, 3 journal for each SSD OSD: 6 SAS10K 900G (SAS2 6Gbps), each running an OSD process. Total size for OSDs: 5,4TB 2- With journal in a partition in the spinners. OS: 2xSSD intel SC3500 100G Raid 1 OSD+journal: 8 SAS15K 600G (SAS3 12Gbps), each runing an OSD process and its journal. Total size for OSDs: 3,6TB The budget in both configuration is similar, but the total capacity not. What would be the best configuration from the point of view of performance? In the second configuration I know the controller write back cache could be very critical, the servers has a LSI 3108 controller with 2GB Cache. I have to plan this storage as a KVM image backend and the goal is the performance over the capacity. On the other hand, with these new hardware, what would be the best choice: create a new pool in an existing cluster or create a complete new cluster? Are there any advantages in creating and maintaining an isolated new cluster? thanks in advance, Xabier
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