On Sun, 27 Aug 2017 at 17:18:28 -0500
d_pridge <d_pridge@???> wrote:

> Doesn't this affect the expected lifetime for an SSD?

Little. AFAIK this used to be a more serious concern on the first
generation of SSDs, because they suffered strongly from write-wear and
because firmware, drivers and filesystems did not support write-levelling.
Today this is much less of a concern. SSD cells can stand many more write
operations before wearing (not so so called 3D SSD units, however) and unit's
firmware today apply algorithms to write operations that attempt to spread
writes as evenly as possible to cells avoiding impinging too many times on
the same ones. Which means that, even if you're writing several times on the
same filesystem's blocks (e.g., the FS's log on a journalled FS), these
blocks are mapped to cells spread here and there on the SSD that are generally
different from write operation to another, transparently to the filesystem's
driver and block allocator. Plus, SSD-aware filesystems (designed, among
other things, to reduce the impact of write amplification of cells being
rewritten) further help prolonging the unit's life, regardless of how it is
used.


Alessandro