Zram: Difference between revisions

Latest revision as of 18:18, 4 June 2025

This page documents how to set up ZRAM in Alpine Linux. Zram can be used as an alternative to Swap partition.

Install the neccessary packages:

For a basic ZRAM swap, configure ZRAM by editing the file /etc/conf.d/zram-init as follows:

Contents of /etc/conf.d/zram-init

load_on_start=yes
unload_on_stop=yes
num_devices=1
type0=swap
size0=8000

Advanced parameters can be found in the source repo.

Start services:

# rc-service zram-init start

View the ZRAM drive:

# cat /proc/swaps

Check Algorithms:

# cat /sys/block/zram0/comp_algorithm

Advanced setups may also add these parameters to /etc/sysctl.conf as follows:

Contents of /etc/sysctl.conf

vm.page-cluster=0
vm.extfrag_threshold=0
vm.swappiness=100

To ensure that service starts during next reboot:

# rc-update add zram-init

Check whether ZRAM's module is loaded:

# lsmod | grep zram

If not loaded, use modprobe to load it: (however, it should be automatically loaded if load_on_start=yes is in the configuration)

# modprobe zram

@@ Line 7: / Line 7: @@
 == 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>num_devices=1
+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
-size0=8000 </nowiki>}}
+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}}
@@ Line 23: / Line 29: @@
 == Troubleshooting ==
+Check whether ZRAM's module is loaded: {{Cmd|# lsmod &#124; 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 ==