On Fri, May 29, 2020 at 6:57 PM Jason Dillaman <jdillama@xxxxxxxxxx> wrote:
>
> lgtm -- couple questions:
>
> 1) the client adding the options will be responsible for determining if it's safe to enable read-from-replica/balanced reads (i.e. OSDs >= octopus)?
Yes, we can't easily check require_osd_release or similar in the
kernel. This is opt-in, and I'll add a warning together with the
description of the new options to the man page.
> 2) is there a way to determine if the kernel supports the new options (or will older kernels just ignore the options w/o complaining)? i.e. can ceph-csi safely add the argument regardless?
No, older kernels will error out. I think ceph-csi would handle
this the same way ceph quotas are handled (i.e. with the list of
known "good" kernel versions) or alternatively just attempt to map
with and then without crush_location and read_balance=localize
(probably less appealing given that the kernel version list
infrastructure is already in place).
Thanks,
Ilya
