Qubes in tmpfs 🀫

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For RAM saving, you can use a compressed RAM-based block device - zram kernel module instead of tmpfs. There is approximately 45% compression ratio for root directory (/) :

Demonstration:

user@dom0 ~ % zramctl

NAME       ALGORITHM DISKSIZE DATA COMPR TOTAL STREAMS MOUNTPOINT
/dev/zram0 lzo-rle        10G   7G  3.1G  3.2G       8 /

user@dom0 ~ % zramctl -h
...
DATA  uncompressed size of stored data
COMPR  compressed size of stored data
...

Setup actions:

  1. Add + lines, remove - line in our (mentioned earlier) file /usr/lib/dracut/modules.d/01ramboot/tmpfs.sh :
-               mount -t tmpfs -o size=100% none /sysroot
+               modprobe zram
+               echo 10G > /sys/block/zram0/disksize
+               /mnt/usr/sbin/mkfs.ext2 /dev/zram0
+               mount /dev/zram0 /sysroot
  1. Add line to our file /etc/dracut.conf.d/ramboot.conf :
add_drivers+=" zram "
  1. Regenerate the /boot/initramfs… and reboot.
user@dom0 ~ % sudo dracut --verbose --force
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