1 Feb
2023
1 Feb
'23
5:17 p.m.
On Wed, Feb 1, 2023 at 10:13 AM emanuel stiebler <emu(a)e-bbes.com> wrote:
On 2023-02-01 10:56, Warner Losh wrote:
That's selectable at the controller level... But there's no standard way for
the OS to turn that from one to the other... Unless you go all in and do all
the management which some NVMe drives support (not the ones we buy,
mind you, since this is an 'enterprise' feature and we buy in the
'consumer'
space).
On Wed, Feb 1, 2023 at 1:41 AM emanuel stiebler via cctalk
<cctalk(a)classiccmp.org <mailto:cctalk@classiccmp.org>> wrote:
retension in case of power off.
If the power is applied all the time, the internal controller "can"
check the quality of the cells automatically (but this really
depends on
the controller, controller version, and the OS has to chose the right
strategy. And the controllers improved a lot lately)
The OS might not have a choice. All the SSDs that I've used in the
past decade at $WORK have not exposed any of this to the host, not
even enough stats to know when it's going on in real time... let alone
the ability to pause these operations for a little while until we're off
peak for the day...
But you should be able to choose (at least on controllers I know) if you
like to go for automatic or manual refresh.
If you go for the automatic, it could happen that the
drive decides to
scan the drive, when your're busy and going nuts waiting for the drive
(you can also define on newer drives how many block to check per run)
If you're going for the manual refresh, just make sure you really run it
one day. But, you should be the one who knows, when your computer isn't
busy ...
We'd like to be able to do that, but the drives we buy don't expose those
knobs, despite buying many different models over the years from the same
vendors and developing a close relationship with them in which we ask for
it every chance we get...
Warner