Re: Wiping an unencrypted SSD in preparation for encryption

[rhkramer@gmail.com]

Darn, please ignore the previous message -- didn't mean to send, was working 
on a draft, meant to save as a draft instead of send.

(Of course, if you want to reply, feel free.)

On Friday, June 11, 2021 11:01:40 AM rhkramer@gmail.com wrote:
> On Friday, June 11, 2021 02:49:03 AM Reco wrote:
> > On Thu, Jun 10, 2021 at 11:43:12PM -0700, David Christensen wrote:
> > > I don't bother with the 'discard' option in /etc/fstab, but perhaps I
> > > should.  The fstab(5) and mount(8) manual pages are unclear if
> > > 'discard' applies to swap or ext4.
> > 
> > swapon(8):
> >    -d, --discard[=policy]
> >    
> > 	  Enable  swap  discards ... The /etc/fstab mount options discard,
> > 
> > discard=once, or discard=pages may also be used to enable discard flags.
> 
> So, I'm not clear on what happens if you don't use the discard option.  I
> assume that the data in swap is swapped back (written back) to the proper
> location in RAM before reusing the swap space, which would be unnecessary
> if the
> 
> 
>        -d, --discard
>               Discard freed swap pages before they are reused, if the swap
> device supports the discard or trim operation.  This may improve
> performance on some  Solid  State  Devices, but  often  it  does  not.  
> The  /etc/fstab mount option discard may be also used to enable discard
> flag.