On Thu, Jan 23, 2020 at 3:31 PM Hayashida, Mami <mami.hayashida(a)uky.edu> wrote:
Thanks, Ilya.
First, I was not sure whether to post my question on @ceph.io or @lists.ceph.com (I
subscribe to both) -- should I use @ceph.io in the future?
Yes. I got the following when I replied to your previous email:
As you may or may not be aware, most of the Ceph mailing lists have
migrated to a new self-hosted instance of Mailman 3. For the past few
months, both this list and ceph-users(a)ceph.io have been enabled.
As of January 22, 2020, mail sent to ceph-users(a)lists.ceph.com will no
longer be delivered. This domain will remain so that permalinks to
archives are preserved.
Please use the new address ceph-users(a)ceph.io instead.
Second, thanks for your advice on cache-tiering -- I was starting to feel that way but
always good to know what Ceph "experts" would say.
Third, I tried enabling (and setting) the pool application commands you outlined but got
errors (Ceph is not allowing me to enable/set application on the cache tier)
$ ceph osd pool application enable cephfs-data-cache cephfs
Error EINVAL: application must be enabled on base tier
$ ceph osd pool application set cephfs-data-cache cephfs data cephfs_test
Error EINVAL: application metadata must be set on base tier
Since at this point, it is highly unlikely that we will be utilizing cache-tier on our
production clusters, and there is a work around it (by manually creating a CephFS client
key), this is nothing serious or urgent; but I thought I should let you guys know.
I haven't actually tried it. There is probably a way to make it work
(recreating the pools and doing the application stuff before tiering or
something along those lines), but yeah, cache tiering is not without
sharp edges...
Thanks,
Ilya