On Mar 4, 2016 5:30 PM, "Christian Balzer" <chibi@xxxxxxx> wrote:
>
> On Fri, 4 Mar 2016 16:09:17 +0900 Shinobu Kinjo wrote:
>
> > Comparing with these SSDs,
> >
> > S3710s
> > S3610s
> > SM863
> > 845DC Pro
> >
> > which one is more reasonable in terms of performance, cost or whatever?
> > S3710s does not sound reasonable to me.
> >
> Apples and Oranges.
> I use S3700s (I would use 3710s only if larger than 200GB, which I have no
This evaluation is interesting to me.
> use case for now) exclusively for journals, especially when I can't
> control the write usage/patterns.
> Their speed and endurance is worth the money in my book.
>
> I use S3610s for a cache pool, because the price/performance is right, the
> endurance is sufficient and the write patterns/volume is well known and
> predictable.
I am just thinking of this for my next testing cluster.
>
> > > And I had no luck at all getting the newer versions into a generic
> > > kernel or Debian.
> >
> > So it's not always better to use newer version. Is my understanding
> > right? If I don't understand that properly, point it out to me. I'm
> > pretty serious about that.
> >
> The problem was getting their module to compile/integrate as it was
> against kernel versions I did not/could not use.
This is good to know.
> Newer LSI/Avago kernel drivers and firmware are definitely recommended,
> given the problems the older stuff has.
>
Thanks for your suggestion.
I will definitely do this.
S
> Christian
> > Cheers,
> > Shinobu
> >
> >
> > On Fri, Mar 4, 2016 at 3:17 PM, Christian Balzer <chibi@xxxxxxx> wrote:
> > >
> > > Hello,
> > >
> > > On Mon, 29 Feb 2016 15:00:08 -0800 Heath Albritton wrote:
> > >
> > >> > Did you just do these tests or did you also do the "suitable for
> > >> > Ceph" song and dance, as in sync write speed?
> > >>
> > >> These were done with libaio, so async. I can do a sync test if that
> > >> helps. My goal for testing wasn't specifically suitability with ceph,
> > >> but overall suitability in my environment, much of which uses async
> > >> IO.
> > >>
> > > 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.
> > >
> > >>
> > >> >> SM863 Pro (default over-provisioning) ~7k IOPS per thread (4
> > >> >> threads, QD32) Intel S3710 ~10k IOPS per thread
> > >> >> 845DC Pro ~12k IOPS per thread
> > >> >> SM863 (28% over-provisioning) ~18k IOPS per thread
> > >> >>
> > >> > Very interesting.
> > >> > To qualify your values up there, could you provide us with the exact
> > >> > models, well size of the SSD will do.
> > >>
> > >> SM863 was 960GB, I've many of these and the 1.92TB models deployed
> > >> 845DC Pro, 800GB
> > >> S3710, 800GB
> > >>
> > > Thanks, pretty much an oranges with oranges comparison then. ^o^
> > >
> > >> > Also did you test with a S3700 (I find the 3710s to be a slight
> > >> > regression in some ways)?
> > >> > And for kicks, did you try over-provisioning with an Intel SSD to
> > >> > see the effects there?
> > >>
> > >> These tests were performed mid-2015. I requested an S3700, but at
> > >> that point, I could only get the S3710. I didn't test the Intel with
> > >> increased over-provisioning. I suspect it wouldn't have performed
> > >> much better as it was already over-provisioned by 28% or thereabouts.
> > >>
> > > 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.
> > >
> > >> It's easy to guess at these sort of things. The total capacity of
> > >> flash is in some power of two and the advertised capacity is some
> > >> power of ten. Manufacturer's use the difference to buy themselves
> > >> some space for garbage collection. So, a terabyte worth of flash is
> > >> 1099511627776 bytes. 800GB is 8e+11 bytes with the difference of
> > >> about 299GB, which is the space they've set aside for GC.
> > >>
> > > Ayup, that I was quite aware of.
> > >
> > >> Again, if there's some tests you'd like to see done, let me know.
> > >> It's relatively easy for me to get samples and the tests are a benefit
> > >> to me as much as any other.
> > >>
> > > Well, see above, diminishing returns and all.
> > >
> > >>
> > >> >> I'm seeing the S3710s at ~$1.20/GB and the SM863 around $.63/GB.
> > >> >> As such, I'm buying quite a lot of the latter.
> > >> >
> > >> > I assume those numbers are before over-provisioning the SM863, still
> > >> > quite a difference indeed.
> > >>
> > >> Yes, that's correct. Here's some current pricing: Newegg has the
> > >> SM863 960GB at $565 or ~$.59/GB raw. With 28% OP, that yields around
> > >> 800GB and around $.71/GB
> > >>
> > > 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've not had them deployed
> > >> >> for very long, so I can't attest to anything beyond my synthetic
> > >> >> benchmarks. I'm using the LSI 3008 based HBA as well and I've had
> > >> >> to use updated firmware and kernel module for it. I haven't
> > >> >> checked the kernel that comes with EL7.2, but 7.1 still had
> > >> >> problems with the included driver.
> > >> >>
> > >> > Now THIS is really interesting.
> > >> > As you may know several people on this ML including me have issues
> > >> > with LSI 3008s and SSDs, including Samsung ones.
> > >> >
> > >> > Can you provide all the details here, as in:
> > >> > IT or IR mode (IT I presume)
> > >> > Firmware version
> > >> > Kernel driver version
> > >>
> > >> When initially deployed about a year ago, I had problems with SSDs and
> > >> spinning disks. Not sure about any problems specific to Samsung SSDs,
> > >> but I've been on the upgrade train.
> > >>
> > >> 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).
> > >
> > > Thanks,
> > >
> > > Christian
> > > --
> > > Christian Balzer Network/Systems Engineer
> > > chibi@xxxxxxx Global OnLine Japan/Rakuten Communications
> > > http://www.gol.com/
> > > _______________________________________________
> > > ceph-users mailing list
> > > ceph-users@xxxxxxxxxxxxxx
> > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
> >
> >
> >
>
>
> --
> Christian Balzer Network/Systems Engineer
> chibi@xxxxxxx Global OnLine Japan/Rakuten Communications
> http://www.gol.com/
_______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
