A deep archive cluster benefits from NVMe too. You can use QLC up to 60TB in size, 32 of those in one RU makes for a cluster that doesn’t take up the whole DC.
> On Apr 21, 2024, at 5:42 AM, Darren Soothill <darren.sooth...@croit.io> wrote: > > Hi Niklaus, > > Lots of questions here but let me tray and get through some of them. > > Personally unless a cluster is for deep archive then I would never suggest > configuring or deploying a cluster without Rocks DB and WAL on NVME. > There are a number of benefits to this in terms of performance and recovery. > Small writes go to the NVME first before being written to the HDD and it > makes many recovery operations far more efficient. > > As to how much faster it makes things that very much depends on the type of > workload you have on the system. Lots of small writes will make a significant > difference. Very large writes not as much of a difference. > Things like compactions of the RocksDB database are a lot faster as they are > now running from NVME and not from the HDD. > > We normally work with a upto 1:12 ratio so 1 NVME for every 12 HDD’s. This > is assuming the NVME’s being used are good mixed use enterprise NVME’s with > power loss protection. > > As to failures yes a failure of the NVME would mean a loss of 12 OSD’s but > this is no worse than a failure of an entire node. This is something Ceph is > designed to handle. > > I certainly wouldn’t be thinking about putting the NVME’s into raid sets as > that will degrade the performance of them when you are trying to get better > performance. > > > > Darren Soothill > > > Looking for help with your Ceph cluster? Contact us at https://croit.io/ > > croit GmbH, Freseniusstr. 31h, 81247 Munich > CEO: Martin Verges - VAT-ID: DE310638492 > Com. register: Amtsgericht Munich HRB 231263 > Web: https://croit.io/ | YouTube: https://goo.gl/PGE1Bx > > > > > _______________________________________________ > ceph-users mailing list -- ceph-users@ceph.io > To unsubscribe send an email to ceph-users-le...@ceph.io _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-le...@ceph.io
