[gpfsug-discuss] Online data migration tool

Fri Dec 1 12:53:21 GMT 2017

Bill, could you say something about what the metadata-storage here was?
ESS/NL-SAS/3way replication?

I just asked about this in the internal slack channel #scale-help today..

-jf

fre. 1. des. 2017 kl. 13:44 skrev Bill Hartner <bhartner at us.ibm.com>:

> > "It has a significant performance penalty for small files in large
> > block size filesystems"
>
> Aaron,
>
> Below are mdtest results for a test we ran for CORAL - file size was 32k.
>
> We have not gone back and ran the test on a file system formatted without
> > 32 subblocks. We'll do that at some point...
>
> -Bill
>
> -- started at 10/28/2017 17:51:38 --
>
> mdtest-1.9.3 was launched with 228 total task(s) on 12 node(s)
> Command line used: /tmp/mdtest-binary-dir/mdtest -d
> /ibm/fs2-16m-10/mdtest-60000 -i 3 -n 294912 -w 32768 -C -F -r -p 360 -u -y
> Path: /ibm/fs2-16m-10
> FS: 128.1 TiB Used FS: 0.3% Inodes: 476.8 Mi Used Inodes: 0.0%
>
> 228 tasks, 67239936 files
>
> SUMMARY: (of 3 iterations)
> Operation Max Min Mean Std Dev
> --------- --- --- ---- -------
> File creation : 51953.498 50558.517 51423.221 616.643
> File stat : 0.000 0.000 0.000 0.000
> File read : 0.000 0.000 0.000 0.000
> File removal : 96746.376 92149.535 94658.774 1900.187
> Tree creation : 1.588 0.070 0.599 0.700
> Tree removal : 0.213 0.034 0.097 0.082
>
> -- finished at 10/28/2017 19:51:54 --
>
> Bill Hartner
> IBM Systems
> Scalable I/O Development
> Austin, Texas
> bhartner at us.ibm.com
> home office 512-784-0980
>
>
> gpfsug-discuss-bounces at spectrumscale.org wrote on 11/29/2017 04:41:48 PM:
>
> > From: Aaron Knister <aaron.knister at gmail.com>
>
>
> > To: gpfsug main discussion list <gpfsug-discuss at spectrumscale.org>
>
> > Date: 11/29/2017 04:42 PM
>
>
> > Subject: Re: [gpfsug-discuss] Online data migration tool
> > Sent by: gpfsug-discuss-bounces at spectrumscale.org
>
> >
>
> > Thanks, Nikhil. Most of that was consistent with my understnading,
> > however I was under the impression that the >32 subblocks code is
> > required to achieve the touted 50k file creates/second that Sven has
> > talked about a bunch of times:
> >
> >
> http://files.gpfsug.org/presentations/2017/Manchester/08_Research_Topics.pdf
> > http://files.gpfsug.org/presentations/2017/Ehningen/31_-_SSUG17DE_-
> > _Sven_Oehme_-_News_from_Research.pdf
> > http://files.gpfsug.org/presentations/2016/SC16/12_-
> > _Sven_Oehme_Dean_Hildebrand_-_News_from_IBM_Research.pdf
>
>
> > from those presentations regarding 32 subblocks:
> >
> > "It has a significant performance penalty for small files in large
> > block size filesystems"
>
> > although I'm not clear on the specific definition of "large". Many
> > filesystems I encounter only have a 1M block size so it may not
> > matter there, although that same presentation clearly shows the
> > benefit of larger block sizes which is yet *another* thing for which
> > a migration tool would be helpful.
>
> > -Aaron
> >
> > On Wed, Nov 29, 2017 at 2:08 PM, Nikhil Khandelwal <nikhilk at us.ibm.com>
> wrote:
>
> > Hi,
> >
> > I would like to clarify migration path to 5.0.0 from 4.X.X clusters.
> > For all Spectrum Scale clusters that are currently at 4.X.X, it is
> > possible to migrate to 5.0.0 with no offline data migration and no
> > need to move data. Once these clusters are at 5.0.0, they will
> > benefit from the performance improvements, new features (such as
> > file audit logging), and various enhancements that are included in 5.0.0.
> >
> > That being said, there is one enhancement that will not be applied
> > to these clusters, and that is the increased number of sub-blocks
> > per block for small file allocation. This means that for file
> > systems with a large block size and a lot of small files, the
> > overall space utilization will be the same it currently is in 4.X.X.
> > Since file systems created at 4.X.X and earlier used a block size
> > that kept this allocation in mind, there should be very little
> > impact on existing file systems.
> >
> > Outside of that one particular function, the remainder of the
> > performance improvements, metadata improvements, updated
> > compatibility, new functionality, and all of the other enhancements
> > will be immediately available to you once you complete the upgrade
> > to 5.0.0 -- with no need to reformat, move data, or take your data
> offline.
> >
> > I hope that clarifies things a little and makes the upgrade path
> > more accessible.
> >
> > Please let me know if there are any other questions or concerns.
> >
> > Thank you,
> > Nikhil Khandelwal
> > Spectrum Scale Development
> > Client Adoption
> >
> > _______________________________________________
> > gpfsug-discuss mailing list
> > gpfsug-discuss at spectrumscale.org
> > http://gpfsug.org/mailman/listinfo/gpfsug-discuss
>
> > _______________________________________________
> > gpfsug-discuss mailing list
> > gpfsug-discuss at spectrumscale.org
>
> > https://urldefense.proofpoint.com/v2/url?
> >
> u=http-3A__gpfsug.org_mailman_listinfo_gpfsug-2Ddiscuss&d=DwICAg&c=jf_iaSHvJObTbx-
> >
> siA1ZOg&r=Ew59QH6nxuyx6oTs7a8AYX7kKG3gaWUGDGo5ZZr3wQ4&m=DHoqgBeMFgcM0LpXEI0VCYvvb8ollct5aSYUDln2t68&s=iOxGm-853L_W0XkB3jGsGzCTVlSYUvANOTSewcR_Ue8&e=
>
> _______________________________________________
> gpfsug-discuss mailing list
> gpfsug-discuss at spectrumscale.org
> http://gpfsug.org/mailman/listinfo/gpfsug-discuss
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://gpfsug.org/pipermail/gpfsug-discuss_gpfsug.org/attachments/20171201/a6a697b3/attachment-0002.htm>