[CentOS] Utility to zero unused blocks on disk

[Wes James]

> On Feb 8, 2016, at 2:37 PM, Digimer <lists at alteeve.ca> wrote:
> 
> Personally, I just do 'dd if=/dev/zero of=/path/to/zero.img bs=1M; rm -f
> /path/to/zero.img'. It's inelegant, for sure, but it works (note to run
> it as a normal user or else be careful of how your system reacts to
> running out of disk space for a moment).
> 
> fix-it-with-a-hammer-digimer
> 

Looks like it’s working. Thanks.

> On 08/02/16 04:34 PM, Wes James wrote:
>> Is there a utility to zero unused blocks on a disk?
>> 
>> CentOS 6.7/Ext4
>> 
>> I saw zerofree, but I’m not sure it would work on Ext4 or even work on this version of CentOS.