There’s more to it than bottlenecking. RAS, man. RAS.
On Jul 12, 2024, at 3:58 PM, John Jasen <jjasen@gmail.com> wrote:
How large of a ceph cluster are you planning on building, and what network cards/speeds will you be using?
A lot of the talk about RAID HBA pass-through being sub-optimal probably won't be your bottleneck unless you're aiming for a large cluster at 100Gb/s speeds, in my opinion.
On Fri, Jul 12, 2024 at 12:02 PM Drew Weaver <drew.weaver@thenap.com <mailto:drew.weaver@thenap.com>> wrote:
Okay it seems like we don't really have a definitive answer on whether it's OK to use a RAID controller or not and in what capacity.
Passthrough meaning:
Are you saying that it's OK to use a raid controller where the disks are in non-RAID mode? Are you saying that it's OK to use a raid controller where each disk is in its own RAID-0 volume?
I'm just trying to clarify a little bit. You can imagine that nobody wants to be that user that does this against the documentation's guidelines and then something goes terribly wrong.
Thanks again, -Drew
-----Original Message----- From: Anthony D'Atri <aad@dreamsnake.net <mailto:aad@dreamsnake.net>> Sent: Thursday, July 11, 2024 7:24 PM To: Drew Weaver <drew.weaver@thenap.com <mailto:drew.weaver@thenap.com>> Cc: John Jasen <jjasen@gmail.com <mailto:jjasen@gmail.com>>; ceph-users@ceph.io <mailto:ceph-users@ceph.io> Subject: Re: [ceph-users] Repurposing some Dell R750s for Ceph
Isn’t the supported/recommended configuration to use an HBA if you have to but never use a RAID controller?
That may be something I added to the docs. My contempt for RAID HBAs knows no bounds ;)
Ceph doesn’t care. Passthrough should work fine, I’ve done that for tends of thousands of OSDs, albeit on different LSI HBA SKUs.