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Last login: Mon Apr 4 14:42:45 2022 from 156.111.209.231 | Last login: Mon Apr 4 14:42:45 2022 from 156.111.209.231 | ||
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<li>Verify the zram configuration injected by ignition is as expected. | <li>Verify the zram configuration injected by ignition is as expected. | ||
<pre>$ cat /etc/systemd/zram-generator.conf | <pre>[core@d-zram-test-1 ~]$ cat /etc/systemd/zram-generator.conf | ||
<li>This config file enables a /dev/zram0 device with the default settings | <li>This config file enables a /dev/zram0 device with the default settings | ||
[zram0] | [zram0] | ||
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<li>Verify zram has been correctly defined as a swap partition and to the expected size | <li>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. | <p>The default is min(ram/4,4096) which in our 16GB machine instance means 4G. | ||
<pre>[core@d-zram-test-1 ~]$ zramctl --output-all | <pre>[core@d-zram-test-1 ~]$ zramctl --output-all | ||
Revision as of 15:13, 4 April 2022
Description
Install and validate Fedora CoreOS with swap on zram enabled
Setup
- Download and verify the latest FCOS next image (pick the right image for your environment).
- Read background on zram here.
- Figure out how you'd like to configure your initial zram device.
- Read other possible post-boot tests as described here.
How to test
- Create an Ignition file.
- Configure Zram device validating instructions here.
- 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
- 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
- Verify the zram configuration injected by ignition is as expected.
[core@d-zram-test-1 ~]$ cat /etc/systemd/zram-generator.conf <li>This config file enables a /dev/zram0 device with the default settings [zram0]
- 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
- Saturate memory and confirm usage via zramctl
Initially fill memory with 15GB usage and confirm usage via top. No swap.
- Verify the linked documentation makes sense, nothing is obviously missing, and the instructions are clear.
No changes required.
[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