ztab

# Use '#' to comment out any line, add new drives with the first column
# providing the drive type and then drive details separated by tab characters.
#
# All algorithms in '/proc/crypto' are supported but only lzo and lz4 have
# zramctl text strings; lz4 is the fastest with deflate(zlib) having much better
# text compression.
#
# mem_limit is the compressed memory limit and will set a hard memory limit for
# the system admin.
#
# disk_size is the virtual uncompressed size approx. 220-450% of memory
# allocated depending on the algorithm and input file. Don't make it much higher
# than the compression algorithm is capable of as it will waste memory because
# there is a ~0.1% memory overhead when empty
#
# swap_priority will set ZRAM over alternative swap devices.
#
# page-cluster 0 means tuning to singular pages rather than the default 3 which
# caches 8 for HDD tuning, which can lower latency.
#
# swappiness 80 because the improved performance of ZRAM allows more usage
# without any adverse affects from the default of 60. It can be raised up to 100
# but that will increase process queue on intense loads such as boot time.
#
# target_dir is the directory you wish to hold in ZRAM, and the original will be
# moved to a bind mount 'bind_dir' and is synchronized on start, stop, and write
# commands.
#
# bind_dir is the directory where the original directory will be mounted for
# sync purposes. Usually in '/opt' or '/var', name optional.
#
# oldlog_dir will enable log-rotation to an off device directory while retaining
# only live logs in ZRAM. Usually in '/opt' or '/var', name optional.
#
# If you need multiple ZRAM swaps or ZRAM directories, just create another entry
# in this file.
# To do this safely, first stop ZRAM using 'systemctl stop zram-config.service',
# then edit this file.
# Once finished, restart ZRAM using 'systemctl restart zram-config.service'.

# swap	alg	mem_limit	disk_size	swap_priority	page-cluster	swappiness
swap	lz4	250M		750M		75		0		80

# dir	alg	mem_limit	disk_size	target_dir		bind_dir
#dir	lz4	50M		150M		/home/pi		/pi.bind

# log	alg	mem_limit	disk_size	target_dir		bind_dir		oldlog_dir
log	lz4	50M		150M		/var/log		/log.bind		/opt/zram/oldlog