Zram

2025-06-04T18:18:52Z

Ktpss95112: add trouble shooting

This page documents how to set up [https://docs.kernel.org/admin-guide/blockdev/zram.html ZRAM] in Alpine Linux. Zram can be used as an alternative to [[Swap]] partition.

== Installation ==

Install the neccessary packages:{{Cmd|# apk add {{pkg|zram-init}}}}

== Configuration ==

For a basic ZRAM swap, configure ZRAM by editing the file {{path|/etc/conf.d/zram-init}} as follows:{{Cat|/etc/conf.d/zram-init|<nowiki>load_on_start=yes
unload_on_stop=yes
num_devices=1
type0=swap
size0=8000
</nowiki>}}

Advanced parameters can be found in the [https://github.com/vaeth/zram-init/blob/main/openrc/conf.d/zram-init source repo].

Start services:{{Cmd|# rc-service zram-init start}}

View the ZRAM drive:{{Cmd|# cat /proc/swaps}}

Check Algorithms:{{Cmd|# cat /sys/block/zram0/comp_algorithm}}

Advanced setups may also add these parameters to {{path|/etc/sysctl.conf}} as follows:{{Cat|/etc/sysctl.conf|<nowiki>vm.page-cluster=0
vm.extfrag_threshold=0
vm.swappiness=100</nowiki>}}

To ensure that service starts during next reboot: {{Cmd|# rc-update add zram-init}}

== Troubleshooting ==

Check whether ZRAM's module is loaded: {{Cmd|# lsmod | grep zram}}

If not loaded, use <code>modprobe</code> to load it: (however, it should be automatically loaded if <code>load_on_start=yes</code> is in the configuration) {{Cmd|# modprobe zram}}

== See also ==

* [https://github.com/vaeth/zram-init/blob/main/openrc/conf.d/zram-init sample zram-init file on official website]
* [https://wiki.archlinux.org/title/Zram Zram in Arch Wiki]
* [https://en.wikipedia.org/wiki/zram Zram in Wikipedia]

[[Category:System Administration‏‎]]
[[Category:Storage‏‎‏‎]]
[[Category:Kernel]]

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Zram