Hi Wido, thanks for your comments. On Fri, Dec 23, 2016 at 02:00:44PM +0100, Wido den Hollander wrote: > > My original layout was using 2x single Xeon nodes with 24 GB RAM each > > under Proxmox VE for the test application and two metadata servers, > > each as a VM guest. Each VM woud be about 8 GB, 16 GB max. > > > > The VM size doesn't really matter for BlueStore nor did it for XFS/FileStore. The designated metadata servers are LXC VMs, so the question is whether I should give them 8 or 16 MB RAM. I also wonder whether the underlying data store (hardware RAID 1, 7200 rpm SATA) would profit from using SSDs there. Is good I/O important for metadata servers? > > rest as raw partitions for rocksdb and object data. I could boot > > the nodes from an USB memory stick, of course. Would that work, > > or too much I/O still on the slow USB device? > > > > As long as you disable logging you could run on USB sticks. Thanks, I'll try that. > > Before I was limited due to 8 GB RAM to max 8 TB/node, > > so e.g. 2x 4 TB disks. Is this still the case for Bluestore? > > > > Well, the 1GB per 1TB was mainly a PG concern. Storing more data doesn't pers?? use more memory. Placement Groups are the main CPU and Memory consumers. > > Since BlueStore hasn't been used that much the only output comes from devs and what they have tested. > > What I'd say, more memory is always better. When you have memory to spare, put it in there. Would love to, but unbuffered ECC DDR2 is effectively unobtainium these days. It would be better to spend money on used power-efficient servers like R710 which already come with memory and plenty of disk slots. _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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