From Fedora Project Wiki

Revision as of 14:55, 5 April 2022 by Dustymabe (talk | contribs) (Created page with "{{QA/Test_Case |description=Install and validate Fedora CoreOS with swap on zram enabled |setup= # Download and verify the latest [https://getfedora.org/coreos/download?tab=me...")
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

Description

Install and validate Fedora CoreOS with swap on zram enabled

Setup

  1. Download and verify the latest FCOS next image (pick the right image for your environment).
  2. Read background on zram here.
  3. Figure out how you'd like to configure your initial zram device.
  4. Read other possible post-boot tests as described here.

How to test

  1. Create an Ignition file.
  2. Configure Zram device validating instructions here.
  3. Launch your Fedora CoreOS system using this Ignition file. See the Quickstart and the provisioning docs for a guide how to launch FCOS in most environments (bare metal, virtual, cloud, etc).

Expected Results

  1. Verify you can SSH successfully into your FCOS system and that it is on the expected version. 
    $ ssh 172.25.81.173
Fedora CoreOS 36.20220325.1.0
Tracker: https://github.com/coreos/fedora-coreos-tracker
Discuss: https://discussion.fedoraproject.org/tag/coreos

Last login: Mon Apr  4 14:42:45 2022 from 156.111.209.231
  2. Verify the zram configuration injected by ignition is as expected. 
    [core@d-zram-test-1 ~]$ cat /etc/systemd/zram-generator.conf
# This config file enables a /dev/zram0 device with the default settings
[zram0]
  3. Verify zram has been correctly defined as a swap partition and to the expected size

    The default is min(ram/4,4096) which in our 16GB machine instance means 4G. 

    [core@d-zram-test-1 ~]$ zramctl --output-all
zramctl --output-all
NAME       DISKSIZE DATA COMPR ALGORITHM STREAMS ZERO-PAGES TOTAL MEM-LIMIT MEM-USED MIGRATED MOUNTPOINT
/dev/zram0       4G   4K   80B lzo-rle         4          0   12K        0B      12K       0B [SWAP]
[core@d-zram-test-1 ~]$ swapon
NAME       TYPE      SIZE USED PRIO
/dev/zram0 partition   4G   0B  100
  4. Saturate memory and confirm usage via zramctl

    Initially fill memory with 15GB usage and confirm usage via top. No swap.

    5. [core@d-zram-test-1 ~]$ </dev/zero head -c 15G | tail &
[1] 1810
[core@d-zram-test-1 ~]$ sleep 5
[core@d-zram-test-1 ~]$ top -o %MEM -bn1 | head -n 15
top - 14:50:20 up 14 min,  1 user,  load average: 0.60, 0.24, 0.12
Tasks: 125 total,   3 running, 122 sleeping,   0 stopped,   0 zombie
%Cpu(s):  1.6 us,  1.6 sy,  0.0 ni, 95.2 id,  0.0 wa,  0.0 hi,  0.0 si,  1.6 st
MiB Mem :  15994.1 total,    238.0 free,  15687.3 used,     68.9 buff/cache
MiB Swap:   4096.0 total,   4068.9 free,     27.1 used.    109.9 avail Mem

    PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
   1810 core      20   0   15.1g  15.1g   1668 R   6.2  96.4   0:15.48 tail
   1466 root      20   0 1440984  15588   3844 S   0.0   0.1   0:00.27 dockerd
   1475 root      20   0 1345832  14856   2416 S   0.0   0.1   0:01.83 containerd
    773 root      20   0   58856  10444   9236 S   0.0   0.1   0:00.46 systemd-journal
   1513 root      20   0  770212   6928      0 S   0.0   0.0   0:00.16 docker-driver
    848 systemd+  20   0   23984   6688   3256 S   0.0   0.0   0:00.14 systemd-resolve
      1 root      20   0  172348   5396    848 S   0.0   0.0   0:03.69 systemd
   1759 core      20   0   19240   4480   1348 R  12.5   0.0   0:06.30 sshd

    Now add a further 3G of usage which we expect to be fulfilled by swap and therefore zram as the prioritized device. 

    [core@d-zram-test-1 ~]$ </dev/zero head -c 3G | tail &
[2] 1815
[core@d-zram-test-1 ~]$ top -o %MEM -bn1 | head -n 15
top - 14:50:36 up 14 min,  1 user,  load average: 0.65, 0.27, 0.14
Tasks: 126 total,   1 running, 125 sleeping,   0 stopped,   0 zombie
%Cpu(s):  1.5 us,  3.1 sy,  0.0 ni, 95.4 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
MiB Mem :  15994.1 total,    189.2 free,  15760.8 used,     44.1 buff/cache
MiB Swap:   4096.0 total,   1050.6 free,   3045.3 used.     48.7 avail Mem

    PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
   1810 core      20   0   15.1g  12.1g    280 S   6.2  77.7   0:15.87 tail
   1815 core      20   0 3162560   3.0g    264 S   6.2  19.3   0:03.57 tail
   1466 root      20   0 1440984  10548      0 S   0.0   0.1   0:00.27 dockerd
   1475 root      20   0 1345832   9648   2888 S   0.0   0.1   0:01.87 containerd
   1513 root      20   0  770212   6172      0 S   0.0   0.0   0:00.17 docker-driver
   1816 core      20   0    7856   3624   2996 R   0.0   0.0   0:00.00 top
      1 root      20   0  172348   2868      0 S   0.0   0.0   0:03.69 systemd
   1760 core      20   0    6212   2004   1644 S   0.0   0.0   0:00.55 bash
[core@d-zram-test-1 ~]$ zramctl --output-all
NAME       DISKSIZE DATA COMPR ALGORITHM STREAMS ZERO-PAGES TOTAL MEM-LIMIT MEM-USED MIGRATED MOUNTPOINT
/dev/zram0       4G   3G 35.6M lzo-rle         4     381047 43.4M        0B    47.4M      57B [SWAP]
[core@d-zram-test-1 ~]$ swapon
NAME       TYPE      SIZE USED PRIO
/dev/zram0 partition   4G   3G  100
  5. Verify the linked documentation makes sense, nothing is obviously missing, and the instructions are clear.

    No changes required.

Retrieved from "https://fedoraproject.org/w/index.php?title=QA:Testcase_CoreOS_swap_on_zram&oldid=639902"