After problems with mount I run e2fsck -y -b BLOCK /dev/sda and it was running for 3 days on 6TB raid 0, when it completed this was the output:
/dev/sda: ***** FILE SYSTEM WAS MODIFIED *****
/dev/sda: ********** WARNING: Filesystem still has errors **********
/dev/sda: 1529942/122060800 files (7.5% non-contiguous), 9080905/488243200 blocks
So I mounted this virtual drive and it shows now: Total 1.8TiB, Free 1.8TiB, looks like it shows the space that left on my virtual disk before filesystem ext4 crashed. None of harddisks crashed, only filesystem was corrupted. I did not have disk partitioned, only one single virtual disk.
Any way that I could restore files somehow?