Re: Western Digital Red's SMR and btrfs?

[Zygo Blaxell <ce3g8jdj@umail.furryterror.org>]

On Mon, May 11, 2020 at 03:42:44PM -0700, Phil Karn wrote:
> On 5/11/20 14:13, Alberto Bursi wrote:
> >
> > Afaik drive-managed SMR drives (i.e. all drives that disguise
> > themselves as non-SMR) are acting like a SSD, writing in empty "zones"
> > first and then running garbage collection later to consolidate the
> > data. TRIM is used for the same reasons SSDs also use it.
> > This is the way they are working around the performance penalty of
> > SMR, as it's the same limitation NAND flash also has (you can write
> > only a full cell at a time).
> >
> > See here for example
> > https://support-en.wd.com/app/answers/detail/a_id/25185
> >
> > -Alberto
> 
> Right, I understand that (some?) SMR drives support TRIM for the same
> reason that SSDs do (well, a very similar reason). My question was
> whether there'd be any reason for a NON-SMR drive to support TRIM, or if
> TRIM support necessarily implies shingled recording. I didn't know
> shingled recording was in any general purpose 2.5" spinning laptop
> drives like mine, and there's no mention of SMR in the HGST manual.

According to

	https://hddscan.com/blog/2020/hdd-wd-smr.html

2.5" SMR drives appeared in 2016.

> Phil
> 
> 
>