Max partitions vs. disks in Operational considerations in OpenStack Architecture Design Guide

[Radek Bíba]

The document reads:

"... it is important to determine the maximum partition power required by the Object Storage service, which determines the maximum number of partitions which can exist. Object Storage distributes data among all available storage, but a partition cannot span more than one disk, so the maximum number of partitions can only be as high as the number of disks."

The last statement doesn't seem correct because you *can* have much more partitions than disks; e.g. one disk and eight partitions if the partition power is 3, as described in the very next paragraph.

Should that be the other way around? Ie. the maximum number of disks can only be as high as the number of partitions? Or is the maximum number of partitions limited in some other way?

-----------------------------------
Built: 2015-11-04T18:05:02 00:00
git SHA: 631b53aa1f5d3f9d903cce13f38e915535ce348a
URL: http://docs.openstack.org/arch-design/content/operational-considerations-storage-focus.html
source File: file:/home/jenkins/workspace/openstack-manuals-tox-doc-publishdocs/doc/arch-design/storage_focus/section_operational_considerations_storage_focus.xml
xml:id: operational-considerations-storage-focus

[Radek Bíba (rbiba)]

Also, instead of 2^3, please consider using 2<superscript>3</superscript>. The same applies to 2^10, too.

[Alexandra Settle (alexandra-settle)]

The RST conversion of the Arch Guide is currently underway, so hold on this patch until the conversion is complete.

[Giulio Fidente (gfidente)]

As you pointed, I believe the last sentence is wrong as it's the maximum number of devices which can't exceed the number of partitions.

Adding Christian to the bug so that he can review and comment as well.

[Alexandra Settle (alexandra-settle)]

Adding Darren and Ben from our Arch Guide team.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/427337

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/427337
Committed: https://git.openstack.org/cgit/openstack/openstack-manuals/commit/?id=9499a7d2939449f1daeaab222b4349709d9973a6
Submitter: Jenkins
Branch: master

commit 9499a7d2939449f1daeaab222b4349709d9973a6
Author: MikeG451 <email address hidden>
Date: Tue Jan 31 17:48:03 2017 +0000

    Max partitions/disks in Operational considerations Arch Design Guide misworded

    Revise Scaling Object Storage section of Operational considerations in OpenStack
    Architecture Design Guide. Guide uses disks where it should say partitions and
    reword incorrect sentence.

    Change-Id: Ida78a215ad44da65dc254f5f7f39554f1b8b9dbd
    Closes-bug: #1513469

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/openstack-manuals 15.0.0 release.