At /dev/block directory, what's meaning of file name like 8:0 or 11:0?

Question

There's a bunch of symbolic links in /dev/block directory.
And I figured out that they're pointing block device files in /dev.
I wonder meaning of their names(8:0, 8:1, 11:0, 11:1, ...)

Answer 1

If you do a normal ls -l then you'll see these are links to the block devices.

% ls -l /dev/block/
total 0
lrwxrwxrwx 1 root root 6 May  5 09:03 253:0 -> ../vda
lrwxrwxrwx 1 root root 7 May  5 09:03 253:1 -> ../vda1
lrwxrwxrwx 1 root root 6 May  5 09:03 253:16 -> ../vdb
lrwxrwxrwx 1 root root 7 May  5 09:03 253:2 -> ../vda2
lrwxrwxrwx 1 root root 7 May  5 09:03 253:3 -> ../vda3
lrwxrwxrwx 1 root root 6 May  5 09:03 253:32 -> ../vdc
lrwxrwxrwx 1 root root 7 May  5 09:03 253:33 -> ../vdc1

If instead, you do ls -lL then you'll see the target details

% ls -lL /dev/block/
total 0
brw-rw---- 1 root disk 253,  0 May  5 09:03 253:0
brw-rw---- 1 root disk 253,  1 May  5 09:03 253:1
brw-rw---- 1 root disk 253, 16 May  5 09:03 253:16
brw-rw---- 1 root disk 253,  2 May  5 09:03 253:2
brw-rw---- 1 root disk 253,  3 May  5 09:03 253:3
brw-rw---- 1 root disk 253, 32 May  5 09:03 253:32
brw-rw---- 1 root disk 253, 33 May  5 09:03 253:33

From here it's obvious that the x:y values in the filename are the major/minor device numbers.

See also What do device type numbers mean?