:: Re: [DNG] noatime by default
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Lähettäjä: Alessandro Selli
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Vastaanottaja: dng
Aihe: Re: [DNG] noatime by default
On Mon, 28 Aug 2017 at 12:58:24 +0200
Narcis Garcia <informatica@???> wrote:

> El 28/08/17 a les 11:59, Alessandro Selli ha escrit:
>> 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.
>>
>
> "SSD-aware filesystems" are flesystems mounted with no atime


They do more than that:

https://en.wikipedia.org/wiki/Flash_file_system


Alessandro