Re: GPT and SSDs
On Fri, 23 May 2014, Andrei POPESCU wrote:
> On Mi, 21 mai 14, 10:25:08, Efraim Flashner wrote:
> > While slightly wasteful, in practice you don't want to fill up an SSD
> > anyway, and as a group they work best with no more than 75% of the disk
> > filled with data.
>
> Various materials I've been reading seem to suggest
>
> s/filled with data/partitioned/
Any SSD worth the materials wasted in its build will be filesystem-agnostic
and allocate on write, so what it really needs for extra head-room is
sectors you don't write to.
It doesn't matter whether the no-write-zone comes from free space in a
filesystem that doesn't keep shuffling data around just for the heck of it,
or unpartitioned space.
And you only benefit from it on devices where the overprovisioning was not
adequate, or when you need it to last a lot longer than what it was
specified for (useful only for SLC and MLC-based devices. If it is TLC, use
it and use it hard, because that crap doesn't last and it degrades even from
reading).
Note that this does not apply to USB flash sticks, and SD cards. For those,
all bets are off, and the crapiest ones only do wear-leveling on a small
area of the drives so you shouldn't even repartition them, let alone change
the FAT32 filesystem layout (size/number of FAT tables, etc). Exceptions
are the far more expensive SLC-based devices for long-term archival.
--
"One disk to rule them all, One disk to find them. One disk to bring
them all and in the darkness grind them. In the Land of Redmond
where the shadows lie." -- The Silicon Valley Tarot
Henrique Holschuh
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