I am pretty new to Ceph and try to find out if Ceph supports hardware level raid HBAs.
Sadly could not find any information. What I found is, that it is recommended to use plain disks for OSD. But this pushes the requirements to the PCIe, the interfaces of the disk to high bandwidths and the CPU requirements are very high.
Hardware RAID controllers have solved these requirements already and they provide high redundancy based on the setups without eating my PCIe, CPU or any other resources.
So my wished setup would be to have local RAID controller(s), which handle my in disk redundancy at controller level (Raid 5, raid 6) whatever RAID level I need. On top of what RAID LUNs I would like to use Ceph to do the higher level of replication between: host, chassis, rack, row, datacenter or whatever is possible or plannable in CRUSH
- Any experiences in that setup?
- Is it a recommended setup?
- Any in depth documentation for this hardware RAID integration?
Best Answer
You can doesn't mean you should. Mapping RAID LUNs to Ceph is possible, but you inject one extra layer of abstraction and kind of render at least part of Ceph functionality useless.
Similar thread on their mailing list:
http://lists.ceph.com/pipermail/ceph-users-ceph.com/2017-September/021159.html