How to merge several container files in Yandex.Disk. Raid 0 / JBOD / LVM?

Question

Yandex.Disk

ubuntu server. There are 10 (or more) files of 10G each: 10 Yandex.Disk clients have been launched, which synchronize these files block by block to the clouds, each under their own account. What is the best and easiest way to combine these files to get a single 100 GB drive? With the ability to expand space on the fly or very quickly with new 10G containers. Initially, the usual mhddfs was used, but it became necessary to backup files larger than the size of one Yandex.Disk (10 GB). Plus mhddfs was only using array reads because it doesn't know about the 10 GB limit on the size of a single synchronized folder. Upd. Created a block device for each file:
dd if=/dev/zero of=yadisk0 bs=1G count=10

mknod -m 660 /dev/yadisk01 b 7 101
losetup /dev/yadisk01 /data/yadisk01

That is, the system has block devices /dev/yadisk01, /dev/yadisk02, etc.
Now it remains to figure out how best to combine them.

Answer 1

do not
use anything simpler and understandable for backup,
the same backblaze backups any amount of files for 5 bucks a month