Re: Wiping an unencrypted SSD in preparation for encryption
On Fri, Jun 11, 2021 at 05:55:02AM -0700, David Christensen wrote:
> On 6/10/21 11:49 PM, 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.
> >
> >
> > Therefore 'discard' can be applied to both ext4 and swap.
>
> Thank you for the clarification regarding trim and swap.
>
> Where do you see the information for ext4?
You just have to know where to look - ext4(5):
discard/nodiscard
Controls whether ext4 should issue discard/TRIM commands to the
underlying block device when blocks are freed. This is useful for SSD
devices and sparse/thinly-provisioned LUNs, but it is off by default
until sufficient testing has been done.
How exactly this ended in manpages section 5 (which is "File formats and
conventions eg /etc/passwd") is anyone's guess.
Reco
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