[clug] Disk vs file size

[Tony Lewis]

On 8/8/19 5:12 pm, Andrew Janke via linux wrote:
> Hi all,
>
> Let's say I have a filesystem that has a blocksize of 1Mb. Yes, you
> read that right.   And I happened to know that there are a lot of very
> small files in there.
>
> Is there an each way to report how much disk space this is costing me?
> All I can think of is using du or ls across the thing and then back
> calculating.  Also, I don't think I have df access.

Can you use stat?

"stat -c '%b %B' filename" gives the number of blocks and the size in 
bytes of each block:

     $ stat -c '%b %B' /etc/passwd
     8 512

Combine with rough and ready use of find, xarg and bc, and the following 
*might* just give you the size in bytes of the recursive contents of a 
directory:

     ( find /some/path -print0 | xargs -0 stat --printf '( %b * %B ) + ' 
; echo 0 ) | bc

Note, this will include filesystem entries for directories themselves, 
which I understand take some space.  If you don't want that, filter them 
out using the following command:

     ( find /some/path -type f -print0 | xargs -0 stat --printf '( %b * 
%B ) + ' ; echo 0 ) | bc

     tony at neutrino:~$ ( find tmp/ -type f -print0 | xargs -0 stat 
--printf '( %b * %B ) + ' ; echo 0 ) | bc
     1465700352
     tony at neutrino:~$ du -sh tmp/
     1.4G    tmp/

Yeah (holds up thumb, squints) looks about right.

Oh, wait, can you use 'du'?

     tony at neutrino:~$ du -s --block-size=1 tmp/
     1465724928      tmp/

This matches the size, include directories:

     tony at neutrino:~$ ( find tmp/ -print0 | xargs -0 stat --printf '( %b 
* %B ) + ' ; echo 0 ) | bc
     1465724928

Tony