On Sat, Apr 4, 2020 at 4:13 PM <jesper@krogh.cc> wrote:
Offloading the block.db on NVMe / SSD: https://docs.ceph.com/docs/mimic/rados/configuration/bluestore-config-ref/
Pro: Easy to deal with - seem heavily supported. Con: As far as I can tell - this will only benefit the metadata of the osd- not actual data. Thus a data-commit to the osd til still be dominated by the writelatency of the underlying - very slow HDD.
small writes (<= 32kb, configurable) are written to db first and written back to the slow disk asynchronous to the original request. -- 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
Bcache: http://lists.ceph.com/pipermail/ceph-users-ceph.com/2018-June/027713.html
Pro: Closest to the BBWC mentioned above - but with way-way larger cache sizes. Con: It is hard to see if I end up being the only one on the planet using this solution.
Eat it - Writes will be as slow as hitting dead-rust - anything that cannot live with that need to be entirely on SSD/NVMe.
Other?
Thanks for your input.
Jesper _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io