On Tue, Aug 6, 2019 at 7:45 PM Robert LeBlanc <rob...@leblancnet.us> wrote: > We have a 12.2.8 luminous cluster with all NVMe and we want to take some of > the NVMe OSDs and allocate them strictly to metadata pools (we have a problem > with filling up this cluster and causing lingering metadata problems, and > this will guarantee space for metadata operations).
Depending on the workload and metadata size: this might be a bad idea as it reduces parallelism. > In the past, we have done this the old-school way of creating a separate > root, but I wanted to see if we could leverage the device class function > instead. > > Right now all our devices show as ssd rather than nvme, but that is the only > class in this cluster. None of the device classes were manually set, so is > there a reason they were not detected as nvme? Ceph only distinguishes rotational vs. non-rotational for device classes and device-specific configuration options > > Is it possible to add a new device class like 'metadata'? yes, it's just a string, you can use whatever you want. For example, we run a few setups that distinguish 2.5" and 3.5" HDDs. > > If I set the device class manually, will it be overwritten when the OSD boots > up? not sure about this, we run all of our setups with auto-updating on start disabled > Is what I'm trying to accomplish better done by the old-school separate root > and the osd_crush_location_hook (potentially using a file with a list of > partition UUIDs that should be in the metadata pool).? device classes are the way to go here -- Paul Emmerich Looking for help with your Ceph cluster? Contact us at https://croit.io croit GmbH Freseniusstr. 31h 81247 München www.croit.io Tel: +49 89 1896585 90 > Thank you, > Robert LeBlanc > ---------------- > Robert LeBlanc > PGP Fingerprint 79A2 9CA4 6CC4 45DD A904 C70E E654 3BB2 FA62 B9F1 > _______________________________________________ > ceph-users mailing list > ceph-users@lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
