Zram

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

Installation

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