Anthony, I had recently found a reference in the Ceph docs that indicated something like 40GB per TB for WAL+DB space. For a 12TB HDD that comes out to 480GB. If this is no longer the guideline I'd be glad to save a couple dollars. -Dave -- Dave Hall Binghamton University kdhall@xxxxxxxxxxxxxx On Thu, Jun 3, 2021 at 6:10 PM Anthony D'Atri <anthony.datri@xxxxxxxxx> wrote: > > Agreed. I think oh …. maybe 15-20 years ago there was often a wider > difference between SAS and SATA drives, but with modern queuing etc. my > sense is that there is less of an advantage. Seek and rotational latency I > suspect dwarf interface differences wrt performance. The HBA may be a > bigger bottleneck (and way more trouble). > > 500 GB NVMe seems like a lot per HDD, are you using that as WAL+DB with > RGW, or as dmcache or something? > > Depending on your constraints, QLC flash might be more competitive than > you think ;) > > — aad > > > > I suspect the behavior of the controller and the behavior of the drive > firmware will end up mattering more than SAS vs SATA. As always it's best > if you can test it first before committing to buying a pile of them. > Historically I have seen SATA drives that have performed well as far as > HDDs go though. > > > > > > Mark > > > > On 6/3/21 4:25 PM, Dave Hall wrote: > >> Hello, > >> > >> We're planning another batch of OSD nodes for our cluster. Our prior > nodes > >> have been 8 x 12TB SAS drives plus 500GB NVMe per HDD. Due to market > >> circumstances and the shortage of drives those 12TB SAS drives are in > short > >> supply. > >> > >> Our integrator has offered an option of 8 x 14TB SATA drives (still > >> Enterprise). For Ceph, will the switch to SATA carry a performance > >> difference that I should be concerned about? > >> > >> Thanks. > >> > >> -Dave > >> > >> -- > >> Dave Hall > >> Binghamton University > >> kdhall@xxxxxxxxxxxxxx > >> _______________________________________________ > >> ceph-users mailing list -- ceph-users@xxxxxxx > >> To unsubscribe send an email to ceph-users-leave@xxxxxxx > >> > > _______________________________________________ > > ceph-users mailing list -- ceph-users@xxxxxxx > > To unsubscribe send an email to ceph-users-leave@xxxxxxx > _______________________________________________ > ceph-users mailing list -- ceph-users@xxxxxxx > To unsubscribe send an email to ceph-users-leave@xxxxxxx > _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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