Bug 1562278 - zram.service is not enabled on LiveOS
Summary: zram.service is not enabled on LiveOS
Keywords:
Status: NEW
Alias: None
Product: Fedora
Classification: Fedora
Component: LiveCD
Version: 29
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: Matthias Clasen
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks: F29BetaFreezeException
TreeView+ depends on / blocked
 
Reported: 2018-03-30 01:15 UTC by Chris Murphy
Modified: 2018-11-05 00:15 UTC (History)
13 users (show)

Fixed In Version:
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Description Chris Murphy 2018-03-30 01:15:30 UTC
Description of problem:

On netinstall and dvd Fedora ISO install media, zram.service is enabled by default. On LiveOS it's not, but probably would benefit from it.

Version-Release number of selected component (if applicable):
Fedora-Workstation-Live-x86_64-28_Beta-1.1.iso
anaconda 28.22.2-7.fc28

How reproducible:
Always

Steps to Reproduce:
1. Boot Fedora-Workstation-Live-x86_64-28_Beta-1.1.iso
2. systemctl status zram.service
3.

Actual results:

   Loaded: loaded (/usr/lib/systemd/system/zram.service; static; vendor preset: disabled)


Expected results:

Maybe add a line to the service

ConditionKernelCommandLine=rd.live.image

This makes sure it's only triggered on live boots not on installed systems?


Additional info:

Comment 1 Chris Murphy 2018-09-15 18:09:47 UTC
This really should be enabled. Depending on OOM killer in low memory situations is definitely resulting in a bad experience. This service is enabled by default on netinstalls, but for some reason not lives, and it's even more needed for lives which have a much higher memory footprint.

Comment 2 Fedora Blocker Bugs Application 2018-09-17 19:30:21 UTC
Proposed as a Freeze Exception for 29-beta by Fedora user chrismurphy using the blocker tracking app because:

 In low memory (2GB or less) situations it substantially improves the experience with better performance and far less likely OOM killer instances.

zram.service is enabled on netinstall since at least Fedora 28; and I've been testing it in lives by manually starting it, since Fedora 28. So I'm confident this is safe. This FE request is only to enable zram.service in lives, ensuring it is not enabled on installed systems.

Workstation WG issue:
https://pagure.io/fedora-workstation/issue/75

Comment 3 Chris Murphy 2018-09-17 20:01:29 UTC
Although I am +1 FE, I'm confident enough in the behavior of zram.service that we don't really need wide spread beta testing, but it can't hurt to do so.

Summary for the blocker/FE review:

Install environments typically have no swap available until the installer creates and activates it *after* "Begin Installation" is clicked. The zram.service creates a RAM drive that uses LZ4 compression, as swap. The service setup is all user space driven, but the zram block device code is all in the kernel including dynamic allocation, meaning other than 0.1% overhead for creating the zram device, it doesn't actually use any memory until something uses it (i.e. swap is needed).

Further, this does not actually change anything in the installer, it's just that anaconda owns the zram.service and zramswapon scripts that set this up. In fact it will be systemd that will start the service during startup.

Comment 4 Vendula Poncova 2018-09-18 12:57:18 UTC
Anaconda is not responsible for starting the zram.service in Live OS. However, it might be enough to update the kickstart file for Fedora Live Workstation. Reassigning to LiveCD.


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