On Oct 22, 2020, at 9:14 AM, Eneko Lacunza
<elacunza(a)binovo.es> wrote:
Don't stripe them, if one NVMe fails you'll lose all OSDs. Just use 1 NVMe drive
for 2 SAS drives and provision 300GB for WAL/DB for each OSD (see related threads on
this mailing list about why that exact size).
This way if a NVMe fails, you'll only lose 2 OSD.
Also, what size of WAL/DB partitions do you have now, and what spillover size?
Generally agreed against making a single giant striped bucket.
Note this may be a good use for RAID10 on WAL/DB if you are committed to multiple disks.
I generally put WAL/DB on RAID10 boot disks. It’s important to have reliable WAL/DB, but
also important that the machine actually boots in the first place. With enough RAM and
non-interactive use, most of the boot bits will be cached so there is no contention for
the channel.
Happy for any critique on this as well!
Brian