The current documentation tries really hard to convince people to set
both `osd_pool_default_pg_num` and `osd_pool_default_pgp_num` in their
configs, but at least the latter has undesirable side effects on any
Ceph version that has PG autoscaling enabled by default (at least quincy
and beyond).
Assume a cluster with defaults of `64` for `pg_num` and `pgp_num`.
Starting `radosgw` will fail as it tries to create various pools without
providing values for `pg_num` or `pgp_num`. This triggers the following
in `OSDMonitor::prepare_new_pool()`:
- `pg_num` is set to `1`, because autoscaling is enabled
- `pgp_num` is set to `osd pool default pgp_num`, which we set to `64`
- This is an invalid setup, so the pool creation fails
Likewise, `ceph osd pool create mypool` (without providing values for
`pg_num` or `pgp_num`) does not work.
Following this rationale:
- Not providing a default value for `pgp_num` will always do the right
thing, unless you use advanced features, in which case you can be
expected to set both values on pool creation
- Setting `osd_pool_default_pgp_num` in your config breaks pool creation
for various cases
This commit:
- Removes `osd_pool_default_pgp_num` from all example configs
- Adds mentions of the autoscaling and how it interacts with the default
values in various places
For each file that was touched, the following maintenance was also
performed:
- Change interternal spaces to underscores for config values
- Remove mentions of filestore or any of its settings
- Fix minor inconsistencies, like indentation etc.
There is also a ticket which I think is very relevant and fixed by this,
though it only captures part of the broader issue addressed here:
Fixes: https://tracker.ceph.com/issues/47176
Signed-off-by: Conrad Hoffmann <ch@bitfehler.net>
Ceph config option names may use spaces, underscores, or by one reference hyphens
as interstitial separators. Most usage within the doc tree uses underscores,
though example conf files and especially structured lists of options mostly
use spaces. Mostly. Underscores help differentiate the config names from
surrounding text, and moreover facilitate scripting, grep, awk, etc and match
their form in src/common/options.cc.
This PR conforms these occurrences of option names to use interstitial underscores instead of spaces.
Fixes: https://tracker.ceph.com/issues/48301
Signed-off-by: Anthony D'Atri <anthony.datri@gmail.com>
