Re: How to get the size of the loop-device?

[Jari Ruusu <jariruusu@xxxxxxxxxxxxxxxxxxxxx>]

Markus Laire wrote:
> Once I have a working loop device, e.g. /dev/loop5, how can I get the
> size of this device in bytes for bash-script?
> I need this, so that I can create two loop-devices on top on it, like
>   losetup -o 0 -s $halfsize /dev/loop6 /dev/loop5
>   losetup -o $halfsize /dev/loop7 /dev/loop5
> 
> I tried trivial `perl -e 'print -s "/dev/loop5"'`, but it just returns zero.
> 
> There's likely a trivial answer to this, but I havn't been able to find it.

sectors=`blockdev --getsize /dev/loop5`
fullsize=`echo ${sectors}' * 512' | bc`
halfsize=`echo ${sectors}' * 256' | bc`

What are you trying to do?

-- 
Jari Ruusu  1024R/3A220F51 5B 4B F9 BB D3 3F 52 E9  DB 1D EB E3 24 0E A9 DD

-
Linux-crypto:  cryptography in and on the Linux system
Archive:       http://mail.nl.linux.org/linux-crypto/