> On Thu, Mar 3, 2016 at 10:17 PM, Christian Balzer <chibi@xxxxxxx> wrote: > Fair enough. > Sync tests would be nice, if nothing else to confirm that the Samsung DC > level SSDs are suitable and how they compare in that respect to the Intels. I'll do some sync testing next week and maybe gather my other results and put 'em on the web somewhere. > Yeah, my curiosity was mostly if there is similar ratio at work here > (might have made more sense for testing purposes to REDUCE the > overprovisioning of the Intel) and where the point of diminishing returns > is. I don't think you can reduce the over-provisioning below default levels. I've played with the tools from Intel and Samsung and haven't seen an option for this. In fact, the manufacturers aren't very forthcoming about the fact that they are doing any over-provisioning. > If I'm reading the (well hidden and only in the PDF) full specs of the > 960GB 863 correctly it has an endurance of about 3 DWPD, so the comparable > Intel model would be the 3610s. > At least when it comes to endurance. > Would be interesting to see those two in comparison. ^.^ I could test them side-by-side. Given the degree with which the SM863 exceeds the performance of the S3710, I'm not sure the S3610 would fare very well. Frankly, I think some of the limitations are in the flash controller. I'm speculating here based on the spikes I've seen on the Intel units that I've tested. As for endurance, the 845DC Pro was rated at 10DWPD. Again, I was disappointed with the 3DWPD of the successor. I was reassured by the folks at Samsung that with the same level of over-provisioning the SM863 would have the same endurance as the 845DC Pro. Caveat emptor and all that, given that's not really documented anywhere. This makes sense given how wear-leveling works. >> I think the stock kernel module is 4.x something or other and LSA, now >> Avago has released P9 through P12 in the past year. When I first >> started using them, I was on the P9 firmware and kernel module, which >> I built from the sources they supply. At this point most of my infra >> is on the P10 version. I've not tested the later versions. >> >> Everything is IT mode where possible. > Yes, at least until kernel 4.1 the module was the 4.0 version. > And I had no luck at all getting the newer versions into a generic kernel > or Debian. > And when I deployed the machines in question P8 was the latest FW from > Supermicro. > > Kernel 4.4 does have the 9.x module, so I guess that's a way forward at > least on the kernel side of things (which I think is the more likely > culprit). I'm using Supermicro HBAs as well, but getting the drive directly from Avago. On their site, I just look for the firmware for the 9300-8i. I've successfully used their utilities to cross-flash a 3008-based HBA from IR to IT mode. The package also includes an SRPM, which I've found to build relatively easily. IIRC, some mods to the spec file were required, but that's about it. Cheers, Heath _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
 |