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{{admon/important | Comments and Explanations | The page source contains comments providing guidance to fill out each section. They are invisible when viewing this page. To read it, choose the "edit" link.<br/> '''Copy the source to a ''new page'' before making changes!  DO NOT EDIT THIS TEMPLATE FOR YOUR CHANGE PROPOSAL.'''}}
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{{admon/important | Comments and Explanations | The page source contains comments providing guidance to fill out each section. They are invisible when viewing this page. To read it, choose the "view source" link.<br/> '''Copy the source to a ''new page'' before making changes!  DO NOT EDIT THIS TEMPLATE FOR YOUR CHANGE PROPOSAL.'''}}
  
 
<!-- Self Contained or System Wide Change Proposal?
 
<!-- Self Contained or System Wide Change Proposal?
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* changing system defaults
 
* changing system defaults
  
For Self Contained Changes, sections marked as "REQUIRED FOR SYSTEM WIDE CHANGES" are OPTIONAL but FESCo/Wrangler can request more details (especially in case the change proposal category is  
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For Self Contained Changes, sections marked as "REQUIRED FOR SYSTEM WIDE CHANGES" are OPTIONAL but FESCo/Wrangler can request more details (especially in case the change proposal category is improper or updated to System Wide category). For System Wide Changes all fields on this form are required for FESCo acceptance (when applies).   
improper or updated to System Wide category). For System Wide Changes all fields on this form are required for FESCo acceptance (when applies).   
 
  
 
We request that you maintain the same order of sections so that all of the change proposal pages are uniform.
 
We request that you maintain the same order of sections so that all of the change proposal pages are uniform.
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<!-- The actual name of your proposed change page should look something like: Changes/Your_Change_Proposal_Name.  This keeps all change proposals in the same namespace -->
 
<!-- The actual name of your proposed change page should look something like: Changes/Your_Change_Proposal_Name.  This keeps all change proposals in the same namespace -->
  
= LVM Cache Logical Volumes <!-- The name of your change proposal --> =
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= Change Proposal Name <!-- The name of your change proposal --> =
  
 
== Summary ==
 
== Summary ==
<!-- A sentence or two summarizing what this change is and what it will do. This information is used for the overall changeset summary page for each release. -->
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<!-- A sentence or two summarizing what this change is and what it will do. This information is used for the overall changeset summary page for each release.  
LVM can now use fast block devices (e.g. SSDs and PCIe Flash) to improve the performance of larger but slower block devices.  These hierarchical or layered logical volumes are called "Cache Logical Volumes" in LVM.
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Note that motivation for the change should be in the Motivation section below, and this part should answer the question "What?" rather than "Why?". -->
  
 
== Owner ==
 
== Owner ==
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This should link to your home wiki page so we know who you are.  
 
This should link to your home wiki page so we know who you are.  
 
-->
 
-->
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* Name: [[User:FASAcountName| Your Name]]
 
<!-- Include you email address that you can be reached should people want to contact you about helping with your change, status is requested, or technical issues need to be resolved. If the change proposal is owned by a SIG, please also add a primary contact person. -->
 
<!-- Include you email address that you can be reached should people want to contact you about helping with your change, status is requested, or technical issues need to be resolved. If the change proposal is owned by a SIG, please also add a primary contact person. -->
* Name: [[User:agk| Alasdair G. Kergon]]
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* Email: <your email address so we can contact you, invite you to meetings, etc. Please provide your Bugzilla email address if it is different from your email in FAS>
* Email: agk@redhat.com
 
* Name: [[User:dcantrel| David Cantrell]]
 
* Email: dcantrel@redhat.com
 
* Name: [[User:dlehman| Dave Lehman]]
 
* Email: dlehman@fedoraproject.org
 
* Release notes owner: <!--- To be assigned by docs team [[User:FASAccountName| Release notes owner name]] <email address> -->
 
 
<!--- UNCOMMENT only for Changes with assigned Shepherd (by FESCo)
 
<!--- UNCOMMENT only for Changes with assigned Shepherd (by FESCo)
 
* FESCo shepherd: [[User:FASAccountName| Shehperd name]] <email address>
 
* FESCo shepherd: [[User:FASAccountName| Shehperd name]] <email address>
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== Current status ==
 
== Current status ==
* Targeted release: [[Releases/21 | Fedora 21 ]]  
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* Targeted release: [[Releases/<number> | Fedora <number> ]]  
* Last updated: (DATE)
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* Last updated: <!-- this is an automatic macro — you don't need to change this line -->  {{REVISIONYEAR}}-{{REVISIONMONTH}}-{{REVISIONDAY2}}
 
<!-- After the change proposal is accepted by FESCo, tracking bug is created in Bugzilla and linked to this page  
 
<!-- After the change proposal is accepted by FESCo, tracking bug is created in Bugzilla and linked to this page  
 
Bugzilla states meaning as usual:
 
Bugzilla states meaning as usual:
NEW -> change proposal is submitted and announced
 
 
ASSIGNED -> accepted by FESCo with on going development
 
ASSIGNED -> accepted by FESCo with on going development
 
MODIFIED -> change is substantially done and testable
 
MODIFIED -> change is substantially done and testable
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-->
 
-->
 
* Tracker bug: <will be assigned by the Wrangler>
 
* Tracker bug: <will be assigned by the Wrangler>
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* Release notes tracker: <will be assigned by the Wrangler>
  
 
== Detailed Description ==
 
== Detailed Description ==
 +
 
<!-- Expand on the summary, if appropriate.  A couple sentences suffices to explain the goal, but the more details you can provide the better. -->
 
<!-- Expand on the summary, if appropriate.  A couple sentences suffices to explain the goal, but the more details you can provide the better. -->
LVM is now capable of using fast block devices (e.g. SSDs) as write-back or write-though caches for larger slower block devices.  Users can create cache logical volumes to improve the performance of their existing logical volumes or create new cache logical volumes composed of a small and fast device coupled with a large and slow device.  These cache logical volumes can be used with most LVM segment types, including RAID 1/4/5/6/10, linear, stripe and thin pools.
 
  
 
== Benefit to Fedora ==
 
== Benefit to Fedora ==
<!-- What is the benefit to the platform?  If this is a major capability update, what has changed? If this is a new functionality, what capabilities does it bring? Why will Fedora become a better distribution or project because of this proposal?-->
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Users will have the advantage of fast block device speeds with the capacity of larger but slower block devices.
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<!-- What is the benefit to the distributionWill the software we generate be improved? How will the process of creating Fedora releases be improved?
 +
 
 +
      Be sure to include the following areas if relevant:
 +
      If this is a major capability update, what has changed?
 +
          For example: This change introduces Python 5 that runs without the Global Interpreter Lock and is fully multithreaded.
 +
      If this is a new functionality, what capabilities does it bring?
 +
          For example: This change allows package upgrades to be performed automatically and rolled-back at will.
 +
      Does this improve some specific package or set of packages?
 +
          For example: This change modifies a package to use a different language stack that reduces install size by removing dependencies.
 +
      Does this improve specific Spins or Editions?
 +
          For example: This change modifies the default install of Fedora Workstation to be more in line with the base install of Fedora Server.
 +
      Does this make the distribution more efficient?
 +
          For example: This change replaces thousands of individual %post scriptlets in packages with one script that runs at the end.
 +
      Is this an improvement to maintainer processes?
 +
          For example: Gating Fedora packages on automatic QA tests will make rawhide more stable and allow changes to be implemented more smoothly.
 +
      Is this an improvement targeted as specific contributors?
 +
          For example: Ensuring that a minimal set of tools required for contribution to Fedora are installed by default eases the onboarding of new contributors.
 +
 
 +
    When a Change has multiple benefits, it's better to list them all.
 +
 
 +
    Consider these Change pages from previous editions as inspiration:
 +
    https://fedoraproject.org/wiki/Changes/Annobin (low-level and technical, invisible to users)
 +
    https://fedoraproject.org/wiki/Changes/ParallelInstallableDebuginfo (low-level, but visible to advanced users)
 +
    https://fedoraproject.org/wiki/Changes/VirtualBox_Guest_Integration (primarily a UX change)
 +
    https://fedoraproject.org/wiki/Changes/NoMoreAlpha (an improvement to distro processes)
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    https://fedoraproject.org/wiki/Changes/perl5.26 (major upgrade to a popular software stack, visible to users of that stack)
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-->
  
 
== Scope ==
 
== Scope ==
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<!-- What work do other developers have to accomplish to complete the feature in time for release?  Is it a large change affecting many parts of the distribution or is it a very isolated change? What are those changes?-->
 
<!-- What work do other developers have to accomplish to complete the feature in time for release?  Is it a large change affecting many parts of the distribution or is it a very isolated change? What are those changes?-->
  
* Release engineering: N/A (not a System Wide Change) <!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
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* Release engineering: [https://pagure.io/releng/issues #Releng issue number] (a check of an impact with Release Engineering is needed) <!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
<!-- Does this feature require coordination with release engineering (e.g. changes to installer image generation or update package delivery)?  Is a mass rebuid required?  If a rel-eng ticket exists, add a link here.  -->
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<!-- Does this feature require coordination with release engineering (e.g. changes to installer image generation or update package delivery)?  Is a mass rebuild required?  include a link to the releng issue.
 +
The issue is required to be filed prior to feature submission, to ensure that someone is on board to do any process development work and testing, and that all changes make it into the pipeline; a bullet point in a change is not sufficient communication -->
  
 
* Policies and guidelines: N/A (not a System Wide Change) <!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
 
* Policies and guidelines: N/A (not a System Wide Change) <!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
 
<!-- Do the packaging guidelines or other documents need to be updated for this feature?  If so, does it need to happen before or after the implementation is done?  If a FPC ticket exists, add a link here. -->
 
<!-- Do the packaging guidelines or other documents need to be updated for this feature?  If so, does it need to happen before or after the implementation is done?  If a FPC ticket exists, add a link here. -->
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* Trademark approval: N/A (not needed for this Change)
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<!-- If your Change may require trademark approval (for example, if it is a new Spin), file a ticket ( https://fedorahosted.org/council/ ) requesting trademark approval from the Fedora Council. This approval will be done via the Council's consensus-based process. -->
  
 
== Upgrade/compatibility impact ==
 
== Upgrade/compatibility impact ==
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<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
 
<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
* Nothing changes for users following update path.
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N/A (not a System Wide Change)
* The logical volumes using cache will become unavailable from systems using older kernels and LVM. The cache will have to be dropped to grant access for those legacy systems.
 
  
 
== How To Test ==
 
== How To Test ==
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3. What are the expected results of those actions?
 
3. What are the expected results of those actions?
 
-->
 
-->
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<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
 
<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
 +
N/A (not a System Wide Change)
  
To test the feature user will have to:
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== User Experience ==
 +
<!-- If this change proposal is noticeable by users, how will their experiences change as a result?
  
* install the system with cache configured once the Anaconda UI is available
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This section partially overlaps with the Benefit to Fedora section above. This section should be primarily about the User Experience, written in a way that does not assume deep technical knowledge. More detailed technical description should be left for the Benefit to Fedora section.
* converting existing LVs to use SSD cache once the LVM package is updated to include latest upstream patches
 
  
An SSD or other fast block device is recommended to actually increase the speed but the feature will be testable without one as the user may create a cache device from the data disk with effect of decreased performance.
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Describe what Users will see or notice, for example:
 
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  - Packages are compressed more efficiently, making downloads and upgrades faster by 10%.
Information on how to setup cache logical volumes can be found in the lvm(8) man page.
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  - Kerberos tickets can be renewed automatically. Users will now have to authenticate less and become more productive. Credential management improvements mean a user can start their work day with a single sign on and not have to pause for reauthentication during their entire day.
 
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- Libreoffice is one of the most commonly installed applications on Fedora and it is now available by default to help users "hit the ground running".
== User Experience ==
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- Green has been scientifically proven to be the most relaxing color. The move to a default background color of green with green text will result in Fedora users being the most relaxed users of any operating system.
<!-- If this change proposal is noticeable by its target audience, how will their experiences change as a result?  Describe what they will see or notice. -->
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-->
<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
 
Users will enjoy the increased speed of disk storage while keeping capacity of HDD.
 
  
 
== Dependencies ==
 
== Dependencies ==
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<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
 
<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
* Anaconda: Implementation of UI
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N/A (not a System Wide Change)
* Dracut: Module to Detect and install required configuration files and kernel modules
 
  
 
== Contingency Plan ==
 
== Contingency Plan ==
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<!-- If you cannot complete your feature by the final development freeze, what is the backup plan?  This might be as simple as "Revert the shipped configuration".  Or it might not (e.g. rebuilding a number of dependent packages).  If you feature is not completed in time we want to assure others that other parts of Fedora will not be in jeopardy.  -->
 
<!-- If you cannot complete your feature by the final development freeze, what is the backup plan?  This might be as simple as "Revert the shipped configuration".  Or it might not (e.g. rebuilding a number of dependent packages).  If you feature is not completed in time we want to assure others that other parts of Fedora will not be in jeopardy.  -->
* LVM2Changes are already present upstream.  If severe bugs are found, cache can be disabled here.
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* Contingency mechanism: (What to do? Who will do it?) N/A (not a System Wide Change) <!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
* Dracut:  There is already a hardcoded dm-cache installation.  If the detection is not done in time, it will work as is.
 
* Anaconda:  Cache will work even without UI except it will not be configurable by regular users without using command line. Users can also setup cache LVs after installation.
 
* LVM2:  We will need an ability to drop the cache should the cache device fail or become corrupted.  (This can be done using Live CD.)
 
 
 
 
<!-- When is the last time the contingency mechanism can be put in place?  This will typically be the beta freeze. -->
 
<!-- When is the last time the contingency mechanism can be put in place?  This will typically be the beta freeze. -->
* Contingency deadline: beta freeze <!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
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* Contingency deadline: N/A (not a System Wide Change) <!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
 
<!-- Does finishing this feature block the release, or can we ship with the feature in incomplete state? -->
 
<!-- Does finishing this feature block the release, or can we ship with the feature in incomplete state? -->
* Blocks release? No (not a System Wide Change), Yes/No <!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
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* Blocks release? N/A (not a System Wide Change), Yes/No <!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
* Blocks product? - <!-- Applicable for Changes that blocks specific product release/Fedora.next -->
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* Blocks product? product <!-- Applicable for Changes that blocks specific product release/Fedora.next -->
  
 
== Documentation ==
 
== Documentation ==
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<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
 
<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
* Command line: Cache section of the upstream [[https://git.fedorahosted.org/cgit/lvm2.git/tree/man/lvm.8.in#n401| lvm(8)]] man page.
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N/A (not a System Wide Change)  
  
 
== Release Notes ==
 
== Release Notes ==

Latest revision as of 19:52, 14 May 2019

Important.png
Comments and Explanations
The page source contains comments providing guidance to fill out each section. They are invisible when viewing this page. To read it, choose the "view source" link.
Copy the source to a new page before making changes! DO NOT EDIT THIS TEMPLATE FOR YOUR CHANGE PROPOSAL.


Change Proposal Name

Summary

Owner

  • Name: Your Name
  • Email: <your email address so we can contact you, invite you to meetings, etc. Please provide your Bugzilla email address if it is different from your email in FAS>

Current status

  • Targeted release: [[Releases/<number> | Fedora <number> ]]
  • Last updated: 2019-05-14
  • Tracker bug: <will be assigned by the Wrangler>
  • Release notes tracker: <will be assigned by the Wrangler>

Detailed Description

Benefit to Fedora

Scope

  • Proposal owners:
  • Other developers: N/A (not a System Wide Change)
  • Policies and guidelines: N/A (not a System Wide Change)
  • Trademark approval: N/A (not needed for this Change)

Upgrade/compatibility impact

N/A (not a System Wide Change)

How To Test

N/A (not a System Wide Change)

User Experience

Dependencies

N/A (not a System Wide Change)

Contingency Plan

  • Contingency mechanism: (What to do? Who will do it?) N/A (not a System Wide Change)
  • Contingency deadline: N/A (not a System Wide Change)
  • Blocks release? N/A (not a System Wide Change), Yes/No
  • Blocks product? product

Documentation

N/A (not a System Wide Change)

Release Notes