From 773b038fdaa31198c2ae63e20f00e94b82b5eaa6 Mon Sep 17 00:00:00 2001 From: Chris Murphy Date: May 29 2020 17:23:40 +0000 Subject: incorporated suggested edits --- diff --git a/hibernationstatus.md b/hibernationstatus.md index d309000..beaa976 100644 --- a/hibernationstatus.md +++ b/hibernationstatus.md @@ -4,9 +4,9 @@ **Synopsis:** -The Fedora Workstation working group recognizes hibernation can be useful, but due to impediments it's currently not practical to support it. This is a recognition of the current state of affairs, but the working group wishes hibernation could be relied upon, and thinks there is a viable approach for limited support of hibernation in the future. We encourage interested parties to pursue the needed improvements. In the meantime, Workstation Edition won't be constrained by the current status. There are desired enhancements to performance and security that are hindered by the status quo. The working group will re-evaluate when the significant impediments have been adequately addressed. +The Fedora Workstation working group recognizes hibernation can be useful, but due to impediments it's currently not practical to support it. This is a recognition of the current state of affairs, but the working group wishes hibernation could be relied upon, and thinks there is a viable approach for limited support of hibernation in the future. We encourage interested parties to pursue the needed improvements. In the meantime, given that hibernation isn't currently viable, the workstation WG decides that technical decisions will not be constrained by it. Decisions about Workstation's 'out of the box' configuration might conflict with the requirements of hibernation. There are desired enhancements to performance and security that are hindered by the status quo. The working group will re-evaluate when the significant impediments have been adequately addressed. -We would like to see an install time means of enabling hibernation retained via Custom partitioning. If the user chooses to create a swap partition, the installer will include a resume=UUID kernel parameter hint so that the kernel can find the hibernation image. +We will support an install time means of enabling hibernation retained via Custom partitioning. If the user chooses to create a swap partition, the installer will include a resume=UUID kernel parameter hint so that the kernel can find the hibernation image. **Prior discussions in Fedora:** @@ -35,18 +35,18 @@ We would like to see an install time means of enabling hibernation retained via - UEFI Secure Boot is overwhelmingly present and enabled by default on new computers; - kernel lockdown policy inhibits hibernation when Secure Boot is enabled; - ACPI bugs can be transient and difficult to fix or work around; hibernation can mean data loss due to failed entry or exit; -- resource requirements for the permanent swap partition can be excessive, Anaconda history states the reason for the current swap partition size is to accommodate hibernation; +- resource requirements for the permanent swap partition can be excessive, Anaconda history states the reason for the current swap partition size [4] is to accommodate hibernation; - large swap partition exacerbates performance problems in swap heavy workloads. **Necessary enhancements to hibernation:** -- signed and encrypted hibernation image [4]. +- signed and encrypted hibernation image [5]. *Note:* This is the most central nugget needed for limited hibernation support. Encrypted swap is inadequate because encryption alone provides no integrity. Even though there is an authentication component to the encryption, the image can't be said to be authentic -- as-in trustworthy. To provide the required trust and confidentiality, the hibernation image needs to be both signed and encrypted. **Nice to have enhancements to hibernation:** -- dynamic swapfiles created and enabled prior to hibernation entry [5]; +- dynamic swapfiles created and enabled prior to hibernation entry [6]; - single interface for determining the location of the hibernation image for all file systems [6]; - TPM2 support, or alternative, for storing the key(s) needed to resume. @@ -62,15 +62,18 @@ We would like to see an install time means of enabling hibernation retained via [LWN: Short waits with umwait](https://lwn.net/Articles/790920/) [LWN: The pseudo cpuidle driver](https://lwn.net/Articles/820870/) -[4] - Joey Lee @ SUSE recently confirmed [this lkml email](https://lkml.org/lkml/2019/7/10/601) is the latest status of that work. +[4] RAM to swap ratio is typically 1:1 although there is a cap at 64G. +https://github.com/rhinstaller/anaconda/blob/master/pyanaconda/core/storage.py#L299 [5] + Joey Lee @ SUSE recently confirmed [this lkml email](https://lkml.org/lkml/2019/7/10/601) is the latest status of that work. + +[6] Developing this means hibernation capability could be enabled post-install, and more easily serve competing use cases. Use cases that don't need hibernation would avoid the space wasted for a dedicated and unused swap partition. Use cases that need hibernation would be supported without a swap partition being created at install time. https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/MML5MAKBFNEXBT67TCOVUWGFNOUDYUUP/ https://pagure.io/fedora-workstation/issue/120#comment-618549 -[6] +[7] https://github.com/systemd/systemd/issues/11939#issuecomment-471684411