|
|
| Line 1: |
Line 1: |
| = Feature Name SSDcache =
| |
|
| |
|
| == Summary ==
| |
| Using recent kernel (3.9 and later) features for (fast) SSD caching of (slow) ordinary hard disks.
| |
|
| |
| == Owner ==
| |
| * Name: [[User:rolffokkens|Rolf Fokkens]]
| |
| * Email: rolf@rolffokkens.nl
| |
|
| |
| == Current status ==
| |
| * Targeted release: [[Releases/20|Fedora 20]]
| |
| * Last updated: 20130523
| |
| * Percentage of completion: 0%
| |
|
| |
| == Detailed Description ==
| |
| Recent Linux kernels support the use of Solid State Drives as caches for rotational hard disks. Because the high cost per GB for SSD devices this feature may bring the best of both: fast end big yet affordable storage capacity. Linux kernel 3.9 introduced dm-cache, kernel 3.10 introduces bcache.
| |
|
| |
| == Benefit to Fedora ==
| |
| In general operating systems increasingly (will) support SSD caching, because of it's value to users: an affordable solution for both fast and large storage.
| |
|
| |
| == Scope ==
| |
| Several tools are in scope:
| |
| * Dracut (to support SSD caching for root FS)
| |
| * Anaconda (to support SSD caching in clean installs)
| |
| * bcache-tools (a new package to support bcache)
| |
| * udev (for auto detection of bcache devices)
| |
|
| |
| <!-- What work do the 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?-->
| |
|
| |
| == How To Test ==
| |
| <!-- This does not need to be a full-fledged document. Describe the dimensions of tests that this feature is expected to pass when it is done. If it needs to be tested with different hardware or software configurations, indicate them. The more specific you can be, the better the community testing can be.
| |
|
| |
| Remember that you are writing this how to for interested testers to use to check out your feature - documenting what you do for testing is OK, but it's much better to document what *I* can do to test your feature.
| |
|
| |
| A good "how to test" should answer these four questions:
| |
|
| |
| 0. What special hardware / data / etc. is needed (if any)?
| |
| 1. How do I prepare my system to test this feature? What packages
| |
| need to be installed, config files edited, etc.?
| |
| 2. What specific actions do I perform to check that the feature is
| |
| working like it's supposed to?
| |
| 3. What are the expected results of those actions?
| |
| -->
| |
|
| |
| == User Experience ==
| |
| Users will experience improved disk performance without explicitly having to decide what to store an fast and what to store on slow media.
| |
|
| |
| == Dependencies ==
| |
| This feature relies on the packages as mentioned below:
| |
|
| |
| {|
| |
| ! Component !! Details
| |
| |-
| |
| | anaconda || cache handling during install is needed
| |
| |-
| |
| | dracut || cache handling during boot is needed
| |
| |-
| |
| | bcache-tools || software can be downloaded [https://github.com/g2p/bcache-tools here] and [http://evilpiepirate.org/git/bcache-tools.git here]
| |
| |-
| |
| | kernel || Some [http://www.phoronix.com/scan.php?page=news_item&px=MTM2ODM background info]
| |
| |-
| |
| | udev || [https://github.com/g2p/bcache-tools/commit/0b2587b5bc3869cb96161273c32c9fe6be93b6e1 integration in udev]
| |
| |}
| |
|
| |
| == Contingency Plan ==
| |
| None necessary, revert to previous release behaviour.
| |
|
| |
| == Documentation ==
| |
| The feature is very new, some documentation is in the kernel sources.
| |
|
| |
| Here are some links to [https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/plain/Documentation/device-mapper/cache.txt dm-cache]
| |
| and [http://evilpiepirate.org/git/linux-bcache.git/tree/Documentation/bcache.txt bcache]
| |
|
| |
| == Release Notes ==
| |
| <!-- The Fedora Release Notes inform end-users about what is new in the release. Examples of past release notes are here: http://docs.fedoraproject.org/release-notes/ -->
| |
| <!-- The release notes also help users know how to deal with platform changes such as ABIs/APIs, configuration or data file formats, or upgrade concerns. If there are any such changes involved in this feature, indicate them here. You can also link to upstream documentation if it satisfies this need. This information forms the basis of the release notes edited by the documentation team and shipped with the release. -->
| |
| *
| |
|
| |
| == Comments and Discussion ==
| |
| * See [[Talk:Features/SSDcache]]
| |
|
| |
| [[Category:FeaturePageIncomplete]]
| |
