$ zramctl -s 1G /dev/zram0
$ mkfs.ext4 /dev/zram0
$ mount /dev/zram0 /mnt/
$ sh test.sh
-rw-r--r-- 1 root root 5016838 Feb  3 04:32 /lib/aarch64-linux-gnu/libc.a
cp: error writing '/mnt/201': No space left on device
$ zramctl /dev/zram0
NAME       ALGORITHM DISKSIZE   DATA COMPR  TOTAL STREAMS MOUNTPOINT
/dev/zram0 lzo-rle         1G 866.9M  413M 422.7M       4 /mnt
