[Beowulf] Suggestions to what DFS to use

Douglas O'Flaherty douglasof at gmail.com
Thu Feb 16 06:55:09 PST 2017

A couple of things I see in this thread:

1. Metadata performance!  A lot of bioinformatics code uses metadata
searches. Anyone doing these kinds of workloads should tune/spec for
metadata separately from data storage. In Spectrum Scale there is a choice
of dedicated, fully distributed or partially distributed metadata. Most bio
houses I know choose to through really good flash dedicated to the
Not familiar with the options for BeeFS, but do know superior distributed
metadata performance was a key target for the Fraunhofer team. Sounds like
they are hitting it. My limited history with Ceph & Gluster suggests they
could not support bioinformatic metadata requirements. It wasn't they were
built to do.

2. Small files!  Small file performance is undoubtedly a big gain in IBM
dev from GPFS v 3.x to IBM Spectrum Scale 4.x - Don't compare the old
performance with the new. Spectrum Scale look into the client side caching
for reads and/or writes. A local SSD could be a great boon for performance.
There are lots of tuning options for Scale/GPFS. Small file performance and
simplified install were also target for BeeFS when they started development.

3. Spectrum Scale (GPFS) is absolutely fundamental to IBM. There is a lot
of focus now on making it easier to adopt & tune. IBM dev has delivered new
GUI, monitoring, troubleshooting, performance counters, parameterization of
tuning in the last 18 months.

4. IBM Spectrum Scale does differentiate with multi-cluster, tiered storage
support, migrate data to cloud by policy, HDFS support, etc.  These may be
overkill for a lot of this mailing list, but really useful in shared

Sorry about the guy with the suit. IBM also has a good set of Scale/GPFS
people who don't own ties. Passing along your feedback on the client
license costs to guys with ties.


On Wed, Feb 15, 2017 at 8:43 AM, Scott Atchley <e.scott.atchley at gmail.com>

> Hi Chris,
> Check with me in about a year.
> After using Lustre for over 10 years to initially serve ~10 PB of disk and
> now serve 30+ PB with very nice DDN gear, later this year we will be
> installing 320 PB (250 PB useable) of GPFS (via IBM ESS storage units) to
> support Summit, our next gen HPC system from IBM with Power9 CPUs and
> NVIDIA Volta GPUs. Our current Lustre system is capable of 1 TB/s for large
> sequential writes, but random write performance is much lower (~400 GB/s or
> 40% of sequential). The target performance for GPFS will be 2.5 TB/s
> sequential writes and 2.2 TB/s random (~90% of sequential). The initial
> targets are slightly lower, but we are supposed to achieve these rates by
> 2019.
> We are very familiar with Lustre, the good and the bad, and ORNL is the
> largest contributor to the Lustre codebase outside of Intel. We have
> encountered many bugs at our scale that few other sites can match and we
> have tested patches for Intel before their release to see how they perform
> at scale. We have been testing GPFS for the last three years in preparation
> for the change and IBM has been a very good partner to understand our
> performance and scale issues. Improvements that IBM are adding to support
> the CORAL systems will also benefit the larger community.
> People are attracted to the "free" aspect of Lustre (in addition to the
> open source), but it is not truly free. For both of our large Lustre
> systems, we bought block storage from DDN and we added Lustre on top. We
> have support contracts with DDN for the hardware and Intel for Lustre as
> well as a large team within our operations to manage Lustre and a full-time
> Lustre developer. The initial price is lower, but at this scale running
> without support contracts and an experienced operations team is untenable.
> IBM is proud of GPFS and their ESS hardware (i.e. licenses and hardware are
> expensive) and they also require support contracts, but the requirements
> for operations staff is lower. It is probably more expensive than any other
> combination of hardware/licenses/support, but we have one vendor to blame,
> which our management sees as a value.
> As I said, check back in a year or two to see how this experiment works
> out.
> Scott
> On Wed, Feb 15, 2017 at 1:53 AM, Christopher Samuel <samuel at unimelb.edu.au
> > wrote:
>> Hi John,
>> On 15/02/17 17:33, John Hanks wrote:
>> > So "clusters" is a strong word, we have a collection of ~22,000 cores of
>> > assorted systems, basically if someone leaves a laptop laying around
>> > unprotected we might try to run a job on it. And being bioinformatic-y,
>> > our problem with this and all storage is metadata related. The original
>> > procurement did not include dedicated NSD servers (or extra GPFS server
>> > licenses) so we run solely off the SFA12K's.
>> Ah right, so these are the embedded GPFS systems from DDN. Interesting
>> as our SFA10K's hit EOL in 2019 and so (if our funding continues beyond
>> 2018) we'll need to replace them.
>> > Could we improve with dedicated NSD frontends and GPFS clients? Yes,
>> > most certainly. But again, we can stand up a PB or more of brand new
>> > SuperMicro storage fronted by BeeGFS  that performs as well or better
>> > for around the same cost, if not less.
>> Very nice - and for what you're doing it sounds like just what you need.
>> > I don't have enough of an
>> > emotional investment in GPFS or DDN to convince myself that suggesting
>> > further tuning that requires money and time is worthwhile for our
>> > environment. It more or less serves the purpose it was bought for, we
>> > learn from the experience and move on down the road.
>> I guess I'm getting my head around how other sites GPFS performs given I
>> have a current sample size of 1 and that was spec'd out by IBM as part
>> of a large overarching contract. :-)
>> I guess I assuming that because that was what we had it was how most
>> sites did it, apologies for that!
>> All the best,
>> Chris
>> --
>>  Christopher Samuel        Senior Systems Administrator
>>  VLSCI - Victorian Life Sciences Computation Initiative
>>  Email: samuel at unimelb.edu.au Phone: +61 (0)3 903 55545
>>  http://www.vlsci.org.au/      http://twitter.com/vlsci
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