My vision of a well built node is when number of journal disks is equal to number of data disks. You definitely don't want to lose 3 journals at once in case of single drive failure. > 06 ??? 2014 ?., ? 18:07, Xabier Elkano <xelkano at hostinet.com> ???????(?): > > > 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 > > > _______________________________________________ > ceph-users mailing list > ceph-users at lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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